A Network YANG Data Model for Attachment Circuits

A Network YANG Data Model for Attachment Circuits Orange

mohamed.boucadair@orange.com

Juniper

rroberts@juniper.net

Telefonica

oscar.gonzalezdedios@telefonica.com

Nokia

samier.barguil_giraldo@nokia.com

Huawei Technologies

lana.wubo@huawei.com

Operations and Management Operations and Management Area Working Group Slice Service L3VPN L2VPN This document specifies a network model for attachment circuits. The model can be used for the provisioning of attachment circuits prior or during service provisioning (e.g., VPN, Network Slice Service). A companion service model is specified in I-D.ietf-opsawg-teas-attachment-circuit. The module augments the 'ietf-network' and the Service Attachment Point (SAP) models with the detailed information for the provisioning of attachment circuits in Provider Edges (PEs). Discussion Venues Discussion of this document takes place on the Operations and Management Area Working Group Working Group mailing list (opsawg@ietf.org), which is archived at . Source for this draft and an issue tracker can be found at .

Introduction Connectivity services are provided by networks to customers via dedicated terminating points, such as Service Functions , customer edges (CEs), peer Autonomous System Border Routers (ASBRs), data centers gateways, or Internet Exchange Points. The procedure to provision a service in a service provider network may depend on the practices adopted by a service provider, including the flow put in place for the provisioning of advanced network services and how they are bound to an Attachment Circuit (AC). For example, the same attachment circuit may host multiple services (e.g., Layer 2 Virtual Private Network (VPN), or Layer 3 VPN, or Network Slice Service ). In order to avoid service interference and redundant information in various locations, a service provider may expose an interface to manage ACs network-wide. Customers can then request a standalone attachment circuit to be put in place, and then refer to that attachment circuit when requesting services to be bound to that AC. specifies a data model for managing attachment circuits as a service. specifies a network model for attachment circuits ('ietf-ac-ntw'). The model can be used for the provisioning of ACs prior or during service provisioning. For example, specifies augmentations to the L2VPN Network Model (L2NM) and the L3VPN Network Model (L3NM) to bind LxVPNs to ACs that are provisioned using the procedure defined in this document. The document leverages and by adopting an AC provisioning structure that uses data nodes that are defined in these RFCs. Some refinements were introduced to cover, not only conventional service provider networks, but also specifics of other target deployments (cloud, for example). The AC network model is designed as augmentations to both the 'ietf-network' model and the Service Attachment Point (SAP) model . An attachment circuit can be bound to a single or multiple SAPs. Likewise, the model is designed to accommodate deployments where a SAP can be bound to one or multiple ACs (e.g., a parent AC and its child ACs).

Attachment Circuits Examples The AC network model uses the AC common model defined in . The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in . Sample examples are provided in .

Conventions and Definitions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here. The reader should be familiar with the terms defined in . This document uses the term "network model" as defined in . The meanings of the symbols in the YANG tree diagrams are defined in . LxSM refers to both the Layer 2 Service Model (L2SM) and the Layer 3 Service Model (L3SM) . LxNM refers to both the L2VPN Network Model (L2NM) and the L3VPN Network Model (L3NM) . The following are used in the module prefixes:

ac:: Attachment circuit
ntw:: Network
sap:: Service Attchment Point
svc:: Service

In addition, this document uses the following terms:

Bearer:: A physical or logical link that connects a customer node (or site) to a provider network.
: A bearer can be a wireless or wired link. One or multiple technologies can be used to build a bearer. The bearer type can be specified by a customer.
: The operator allocates a unique bearer reference to identify a bearer within its network (e.g., customer line identifier). Such a reference can be retrieved by a customer and then used in subsequent service placement requests to unambiguously identify where a service is to be bound.
: The concept of bearer can be generalized to refer to the required underlying connection for the provisioning of an attachment circuit.
: One or multiple attachment circuits may be hosted over the same bearer (e.g., multiple Virtual Local Area Networks (VLANs) on the same bearer that is provided by a physical link).
Network controller:: Denotes a functional entity responsible for the management of the service provider network. One or multiple network controllers can be deployed in a service provider network.
Service orchestrator:: Refers to a functional entity that interacts with the customer of a network service.
: A service orchestrator is typically responsible for the attachment circuits, the Provider Edge (PE) selection, and requesting the activation of the requested services to a network controller.
: A service orchestrator may interact with one or more network controllers.
Service provider network:: A network that is able to provide network services (e.g., L2VPN, L3VPN, or Network Slice Services).
Service provider:: A service provider that offers network services (e.g., L2VPN, L3VPN, or Network Slice Services).

Relationship to Other AC Data Models depicts the relationship between the various AC data models:

"ietf-ac-common" ()
"ietf-bearer-svc" ()
"ietf-ac-svc" ()
"ietf-ac-ntw" ()
"ietf-ac-glue" ()

AC Data Models ietf-bearer-svc | ^ ^ | | | | | +------------------------ ietf-ac-ntw | ^ | | | | +----------- ietf-ac-glue -----------+ ]]> "ietf-ac-common" is imported by "ietf-bearer-svc", "ietf-ac-svc", and "ietf-ac-ntw". Bearers managed using "ietf-bearer-svc" may be referenced in the service ACs managed using "ietf-ac-svc". Similarly, a bearer managed using "ietf-bearer-svc" may list the set of ACs that use that bearer. In order to ease correlation between an AC service requests and the actual AC provisioned in the network, "ietf-ac-ntw" uses the AC references exposed by "ietf-ac-svc". To bind Layer 2 VPN or Layer 3 VPN services with ACs, "ietf-ac-glue" augments the LxSM and LxNM with AC service references exposed by "ietf-ac-svc" and AC network references exposed by "ietf-ac-ntw".

Sample Uses of the Attachment Circuit Data Models shows the positioning of the AC network model in the overall service delivery process. The 'ietf-ac-ntw' module is a network model which augments the SAP with a comprehensive set of parameters to reflect the attachment circuits that are in place in a network. The model also maintains the mapping with the service references that are used to expose these ACs to customers . Whether the same naming conventions to reference an AC are used in the service and network layers is deployment-specific.

An Example of the Network AC Model Usage Similar to , the 'ietf-ac-ntw' module can be used for both User-to-Network Interface (UNI) and Network-to-Network Interface (NNI). For example, all the ACs shown in have a 'role' set to 'ietf-sap-ntw:nni'. Typically, AS Border Routers (ASBRs) of each network is directly connected to an ASBR of a neighboring network via one or multiple links (bearers). ASBRs of "Network#1" behave as a PE and treat the other adjacent ASBRs as if it were a CE.

An Example of the Network AC Model Usage Between Provider Networks

Description of the Attachment Circuit YANG Module The full tree diagram of the module can be generated using the "pyang" tool . That tree is not included here because it is too long (). Instead, subtrees are provided in the following subsections for the reader's convenience. The full tree of the 'ac-ntw' is provided in .

Overall Structure of the Module The overall tree structure of the module is shown in .

Overall Tree Structure /nw:networks/network/network-id +--rw ac-parent-ref | +--rw ac-ref? leafref | +--rw node-ref? leafref | +--rw network-ref? -> /nw:networks/network/network-id +--rw peer-sap-id* string +--rw group* [group-id] | +--rw group-id string | +--rw precedence? identityref +--rw status | +--rw admin-status | | +--rw status? identityref | | +--ro last-change? yang:date-and-time | +--ro oper-status | +--ro status? identityref | +--ro last-change? yang:date-and-time +--rw description? string +--rw l2-connection | ... +--rw ip-connection | ... +--rw routing-protocols | ... +--rw oam | ... +--rw security | ... +--rw service ... augment /nw:networks/nw:network/nw:node/sap:service/sap:sap: +--rw ac* [ac-ref] +--rw ac-ref leafref +--rw node-ref? leafref +--rw network-ref? -> /nw:networks/network/network-id ]]> A node can host one or more SAPs. As per , a SAP is an abstraction of the network reference points (the PE side of an AC, in the context of this document) where network services can be delivered and/or are delivered to customers. Each SAP terminates one or multiple ACs. Each AC in turn may be terminated by one or more peer SAPs ('peer-sap'). In order to expose such AC/SAP binding information, the SAP model is augmented with required AC-related information. Unlike the AC service model , an AC is uniquely identified by a name within the scope of a node, not a network. A textual description of the AC may be provided ('description'). Also, in order to ease the correlation between the AC exposed at the service layer and the one that is actually provisioned in the network operation, a reference to the AC exposed to the customer ('ac-svc-ref') is stored in the 'ietf-ac-ntw' module. ACs that are terminated by a SAP are listed in 'ac' under '/nw:networks/nw:network/nw:node/sap:service/sap:sap'. A controller may indicate a filter based on the service type (e.g., Network Slice or L3VPN) to retrieve the list of available SAPs, and thus ACs, for that service. In order to factorize common data that is provisioned for a group of ACs, a set of profiles () can be defined at the network level, and then called under the node level. The information contained in a profile is thus inherited, unless the corresponding data node is refined at the AC level. In such a case, the value provided at the AC level takes precedence over the global one. In contexts where the same AC is terminated by multiple peer SAPs (e.g., an AC with multiple CEs) but a subset of them have specific information, the module allows operators to:

Define a parent AC that may list all these CEs as peer SAPs.
Create individual ACs that are bound to the parent AC using 'ac-parent-ref'.
Indicate for each individual ACs one or a subset of the CEs as peer SAPs. All these individual ACs will inherit the properties of the parent AC.

Whenever a parent AC is deleted, then all child ACs of that AC MUST be deleted. An AC may belong to one or multiple groups . For example, the 'group-id' is used to associate redundancy or protection constraints with ACs. The status of an AC can be tracked using 'status'. Both operational status and administrative status are maintained. A mismatch between the administrative status vs. the operational status can be used as a trigger to detect anomalies. An AC can be characterized using Layer 2 connectivity (), Layer 3 connectivity (), routing protocols (), Operations, Administration, and Maintenance (OAM) (), security (), and service () considerations.

References The AC module defines a set of groupings depicted in for referencing purposes. These references are used within or outside the AC network module. The use of such groupings is consistent with the design in .

References Groupings /nw:networks/network/network-id grouping ac-profile-reference: +-- ac-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id grouping encryption-profile-reference: +-- encryption-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id grouping qos-profile-reference: +-- qos-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id grouping bfd-profile-reference: +-- bfd-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id grouping forwarding-profile-reference: +-- forwarding-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id grouping routing-profile-reference: +-- routing-profile-ref? leafref +-- network-ref? -> /nw:networks/network/network-id ]]> The groupings shown in contain the information necessary to reference:

an attachment circuit that is terminated by a specific node in a given network,
an attachment circuit profile of a specific network (), and
specific provisioning profiles that are bound to a specific network ().

Provisioning Profiles The AC and specific provisioning profiles tree structure is shown in .

Profiles Tree Structure The exact definition of the specific provisioning profiles profiles is local to each service provider. The model only includes an identifier for these profiles in order to ease identifying and binding local policies when building an AC. As shown in , the following identifiers can be included:

'encryption-profile-identifier':: An encryption profile refers to a set of policies related to the encryption schemes and setup that can be applied on the AC.
'qos-profile-identifier':: A Quality of Service (QoS) profile refers to a set of policies such as classification, marking, and actions (e.g., ).
'bfd-profile-identifier':: A Bidirectional Forwarding Detection (BFD) profile refers to a set of BFD policies that can be invoked when building an AC.
'forwarding-profile-identifier':: A forwarding profile refers to the policies that apply to the forwarding of packets conveyed over an AC. Such policies may consist of, for example, applying Access Control Lists (ACLs).
'routing-profile-identifier':: A routing profile refers to a set of routing policies that will be invoked (e.g., BGP policies) for an AC.

L2 Connection The 'l2-connection' container is used to manage the Layer 2 properties of an AC. The Layer 2 connection tree structure is shown in .

Layer 2 Connection Tree Structure The 'encapsulation' container specifies the Layer 2 encapsulation to use (if any) and allows the configuration of the relevant tags. Also, the model supports tag manipulation operations (e.g., tag rewrite). The 'l2-tunnel-service' container is used to specify the required parameters to set a Layer 2 tunneling service (e.g., a Virtual Private LAN Service (VPLS), a Virtual eXtensible Local Area Network (VXLAN), or a pseudowire ()). 'l2vpn-id' is used to identify a L2VPN service that is associated with an Integrated Routing and Bridging (IRB) interface. Specific Layer 2 sub-interfaces may be required to be configured in some implementations/deployments. Such a Layer-2-specific interface can be included in 'l2-termination-point'. To accommodate implementations that require internal bridging, a local bridge reference can be specified in 'local-bridge-reference'. Such a reference may be a local bridge domain. A reference to the bearer is maintained using 'bearer-reference'.

IP Connection This 'ip-connection' container is used to group Layer 3 connectivity information, particularly the IP addressing information, of an AC. The Layer 3 connection tree structure is shown in .

IP Connection Tree Structure A distinct Layer 3 interface other than the interface indicated under the 'l2-connection' container may be needed to terminate the Layer 3 connectivity. The identifier of such an interface is included in 'l3-termination-point'. For example, this data node can be used to carry the identifier of a bridge domain interface. This container can include IPv4, IPv6, or both if dual-stack is enabled. For both IPv4 and IPv6, the IP connection supports three IP address assignment modes for customer addresses: provider DHCP, DHCP relay, and static addressing. Note that for the IPv6 case, Stateless Address Autoconfiguration (SLAAC) can be used. For both IPv4 and IPv6, 'address-allocation-type' is used to indicate the IP address allocation mode to activate for an AC. The allocated address represents the PE interface address configuration. When 'address-allocation-type' is set to 'provider-dhcp', DHCP assignments can be made locally or by an external DHCP server. Such behavior is controlled by setting 'dhcp-service-type'. For IPv6, if 'address-allocation-type' is set to 'slaac', the Prefix Information option of Router Advertisements that will be issued for SLAAC purposes will carry the IPv6 prefix that is determined by 'local-address' and 'prefix-length'. For example, if 'local-address' is set to '2001:db8:0:1::1' and 'prefix-length' is set to '64', the IPv6 prefix that will be used is '2001:db8:0:1::/64'. In some deployment contexts (e.g., network merging), multiple IP subnets may be used in a transition period. For such deployments, multiple ACs (typically, two) with overlapping information may be maintained during a transition period. The correlation between these ACs may rely upon the same 'ac-svc-ref'.

Routing The overall routing subtree structure is shown in .

Routing Tree Structure /nw:networks/network/network-id | | +--rw type? identityref | +--rw static | | ... | +--rw bgp | | ... | +--rw ospf | | ... | +--rw isis | | ... | +--rw rip | | ... | +--rw vrrp | ... +--rw oam | ... +--rw security | ... +--rw service ... ]]> Multiple routing instances ('routing-protocol') can be defined, each uniquely identified by an 'id'. Specifically, each instance is uniquely identified to accommodate scenarios where multiple instances of the same routing protocol have to be configured on the same AC. The type of a routing instance is indicated in 'type'. The values of this attribute are those defined in (the 'routing-protocol-type' identity). Specific data nodes are then provided as a function of the 'type'. See more details in the following subsections. One or multiple routing profiles ('routing-profiles') can be provided for a given routing instance.

Static Routing The static routing subtree structure is shown in .

Static Routing Tree Structure /nw:networks/network/network-id | | +--rw type? identityref | +--rw static | | +--rw cascaded-lan-prefixes | | +--rw ipv4-lan-prefixes* [lan next-hop] | | | {vpn-common:ipv4}? | | | +--rw lan inet:ipv4-prefix | | | +--rw lan-tag? string | | | +--rw next-hop union | | | +--rw metric? uint32 | | +--rw bfd | | | +--rw enable? boolean | | | +--rw bfd-profile-ref? leafref | | | +--rw network-ref? | | | -> /nw:networks/network/network-id | | | +--rw preference? uint32 | | | +--rw status | | | +--rw admin-status | | | | +--rw status? identityref | | | | +--ro last-change? yang:date-and-time | | | +--ro oper-status | | | +--ro status? identityref | | | +--ro last-change? yang:date-and-time | | +--rw ipv6-lan-prefixes* [lan next-hop] | | {vpn-common:ipv6}? | | +--rw lan inet:ipv4-prefix | | +--rw lan-tag? string | | +--rw next-hop union | | +--rw metric? uint32 | | +--rw bfd | | | +--rw enable? boolean | | | +--rw bfd-profile-ref? leafref | | | +--rw network-ref? | | | -> /nw:networks/network/network-id | | +--rw preference? uint32 | | +--rw status | | +--rw admin-status | | | +--rw status? identityref | | | +--ro last-change? yang:date-and-time | | +--ro oper-status | | +--ro status? identityref | | +--ro last-change? yang:date-and-time | +--rw bgp | | ... | +--rw ospf | | ... | +--rw isis | | ... | +--rw rip | | ... | +--rw vrrp | ... +--rw oam | ... +--rw security | ... +--rw service ... ]]> The following data nodes can be defined for a given IP prefix:

'lan-tag':: Indicates a local tag (e.g., "myfavorite-lan") that is used to enforce local policies.
'next-hop':: Indicates the next hop to be used for the static route.
: It can be identified by an IP address, a predefined next-hop type (e.g., 'discard' or 'local-link'), etc.
'bfd':: Indicates whether BFD is enabled or disabled for this static route entry. A BFD profile may also be provided.
'metric':: Indicates the metric associated with the static route entry. This metric is used when the route is exported into an IGP.
'preference':: Indicates the preference associated with the static route entry.
: This preference is used to select a preferred route among routes to the same destination prefix.
'status':: Used to convey the status of a static route entry. This data node can also be used to control the (de)activation of individual static route entries.

BGP The BGP routing subtree structure is shown in .

'name':: Defines a name for the peer group.
'local-address':: Specifies an address or a reference to an interface to use when establishing the BGP transport session.
'description':: Includes a description of the peer group.
'apply-policy':: Lists a set of import/export policies to apply for this group.
'local-as':: Indicates a local AS Number (ASN).
'peer-as':: Indicates the peer's ASN.
'address-family':: Indicates the address family of the peer. It can be set to 'ipv4', 'ipv6', or 'dual-stack'.
: This address family might be used together with the service type that uses an AC (e.g., 'vpn-type' ) to derive the appropriate Address Family Identifiers (AFIs) / Subsequent Address Family Identifiers (SAFIs) that will be part of the derived device configurations (e.g., unicast IPv4 MPLS L3VPN (AFI,SAFI = 1,128) as defined in ).
'multihop':: Indicates the number of allowed IP hops to reach a BGP peer.
'as-override':: If set, this parameter indicates whether ASN override is enabled, i.e., replacing the ASN of the customer specified in the AS_PATH BGP attribute with the ASN identified in the 'local- as' attribute.
'allow-own-as':: Used in some topologies (e.g., hub-and-spoke) to allow the provider's ASN to be included in the AS_PATH BGP attribute received from a peer. Loops are prevented by setting 'allow-own-as' to a maximum number of the provider's ASN occurrences. By default, this parameter is set to '0' (that is, reject any AS_PATH attribute that includes the provider's ASN).
'prepend-global-as':: When distinct ASNs are configured at the node and AC levels, this parameter controls whether the ASN provided at the node level is prepended to the AS_PATH attribute.
'send-default-route':: Controls whether default routes can be advertised to the peer.
'site-of-origin':: Meant to uniquely identify the set of routes learned from a site via a particular AC. It is used to prevent routing loops (). The Site of Origin attribute is encoded as a Route Origin Extended Community.
'ipv6-site-of-origin':: Carries an IPv6 Address Specific BGP Extended Community that is used to indicate the Site of Origin . It is used to prevent routing loops.
'redistribute-connected':: Controls whether the AC is advertised to other PEs.

'bgp-max-prefix': Controls the behavior when a prefix maximum is reached.

'max-prefix':: Indicates the maximum number of BGP prefixes allowed in a session for this group. If the limit is reached, the action indicated in 'violate-action' will be followed.
'warning-threshold':: A warning notification is triggered when this limit is reached.
'violate-action':: Indicates which action to execute when the maximum number of BGP prefixes is reached. Examples of such actions include sending a warning message, discarding extra paths from the peer, or restarting the session.
'restart-timer':: Indicates, in seconds, the time interval after which the BGP session will be reestablished.
'bgp-timers':: Two timers can be captured in this container: (1) 'hold-time', which is the time interval that will be used for the Hold Timer () when establishing a BGP session and (2) 'keepalive', which is the time interval for the KeepaliveTimer between a PE and a BGP peer ().
: Both timers are expressed in seconds.
'capability':: Specifies a set of BGP capabilities (e.g., route refresh capability ) to be enabled per address family.
'bfd':: Indicates whether BFD is enabled or disabled for this nighbor. A BFD profile to apply may also be provided.
'authentication':: The module adheres to the recommendations in , as it allows enabling the TCP Authentication Option (TCP-AO) and accommodates the installed base that makes use of MD5. In addition, the module includes a provision for using IPsec.
: This version of the model assumes that parameters specific to the TCP-AO are preconfigured as part of the key chain that is referenced in the model. No assumption is made about how such a key chain is preconfigured. However, the structure of the key chain should cover data nodes beyond those in , mainly SendID and RecvID ().

For each neighbor, the following data nodes are supported in addition to similar parameters that are provided for a peer group:

'remote-address':: Specifies the remote IP address of a BGP neighbor.
'peer-group':: A name of a peer group.
: Parameters that are provided at the 'neighbor' level takes precedence over the ones provided in the peer group.
'status':: Indicates the status of the BGP session.

OSPF The OSPF routing subtree structure is shown in .

OSPF Routing Tree Structure /nw:networks/network/network-id | | +--rw type? identityref | +--rw static | | ... | +--rw bgp | | ... | +--rw ospf | | +--rw address-family? identityref | | +--rw area-id yang:dotted-quad | | +--rw metric? uint16 | | +--rw sham-links {vpn-common:rtg-ospf-sham-link}? | | | +--rw sham-link* [target-site] | | | +--rw target-site string | | | +--rw metric? uint16 | | +--rw max-lsa? uint32 | | +--rw authentication | | | +--rw enabled? boolean | | | +--rw keying-material | | | +--rw (option)? | | | +--:(auth-key-chain) | | | | +--rw key-chain? | | | | key-chain:key-chain-ref | | | +--:(auth-key-explicit) | | | +--rw key-id? uint32 | | | +--rw key? string | | | +--rw crypto-algorithm? identityref | | +--rw status | | +--rw admin-status | | | +--rw status? identityref | | | +--ro last-change? yang:date-and-time | | +--ro oper-status | | +--ro status? identityref | | +--ro last-change? yang:date-and-time | +--rw isis | | ... | +--rw rip | | ... | +--rw vrrp | ... +--rw oam | ... +--rw security | ... +--rw service ... ]]> The following OSPF data nodes are supported:

'address-family':: Indicates whether IPv4, IPv6, or both address families are to be activated.
: When the IPv4 or dual-stack address family is requested, it is up to the implementation (e.g., network orchestrator) to decide whether OSPFv2 or OSPFv3 is used to announce IPv4 routes.
'area-id':: Indicates the OSPF Area ID.
'metric':: Associates a metric with OSPF routes.
'sham-links':: Used to create OSPF sham links between two ACs sharing the same area and having a backdoor link ( and ).
'max-lsa':: Sets the maximum number of Link State Advertisements (LSAs) that the OSPF instance will accept.
'authentication':: Controls the authentication schemes to be enabled for the OSPF instance. The following options are supported: IPsec for OSPFv3 authentication , and the Authentication Trailer for OSPFv2 and OSPFv3 .
'status':: Indicates the status of the OSPF routing instance.

IS-IS The IS-IS routing subtree structure is shown in .

'address-family':: Indicates whether IPv4, IPv6, or both address families are to be activated.
'area-address':: Indicates the IS-IS area address.
'level':: Indicates the IS-IS level: Level 1, Level 2, or both.
'metric':: Associates a metric with IS-IS routes.
'mode':: Indicates the IS-IS interface mode type. It can be set to 'active' (that is, send or receive IS-IS protocol control packets) or 'passive' (that is, suppress the sending of IS-IS updates through the interface).
: 'authentication':
: Controls the authentication schemes to be enabled for the IS-IS instance. Both the specification of a key chain and the direct specification of key and authentication algorithms are supported.
'status':: Indicates the status of the IS-IS routing instance.

RIP The RIP routing subtree structure is shown in .

'address-family':

Indicates whether IPv4, IPv6, or both address families are to be activated. This parameter is used to determine whether RIPv2 , RIP Next Generation (RIPng), or both are to be enabled .

'timers':

Indicates the following timers (expressed in seconds):

'update-interval':

The interval at which RIP updates are sent.
'invalid-interval':

The interval before a RIP route is declared invalid.
'holddown-interval':

The interval before better RIP routes are released.
'flush-interval':

The interval before a route is removed from the routing table.

'default-metric':

Sets the default RIP metric.

'authentication':

Controls the authentication schemes to be enabled for the RIP instance.

'status':

Indicates the status of the RIP routing instance.

VRRP The VRRP subtree structure is shown in .

'address-family':: Indicates whether IPv4, IPv6, or both address families are to be activated. Note that VRRP version 3 supports both IPv4 and IPv6.
'vrrp-group':: Used to identify the VRRP group.
'backup-peer':: Carries the IP address of the peer.
'virtual-ip-address':: Includes virtual IP addresses for a single VRRP group.
'priority':: Assigns the VRRP election priority for the backup virtual router.
'ping-reply':: Controls whether the VRRP speaker should reply to ping requests.
'status':: Indicates the status of the VRRP instance.

Note that no authentication data node is included for VRRP, as there isn't any type of VRRP authentication at this time (see ).

OAM The OAM subtree structure is shown in .

'dest-addr':: Specifies the BFD peer address.
'source-address':: Specifies the local IP address or interface to use for the session.
'bfd-profile-ref':: Refers to a BFD profile ().
'network-ref':: Includes a network reference to uniquely identify a BFD profile.
'session-type':: Indicates which BFD flavor is used to set up the session (e.g., classic BFD , Seamless BFD ). By default, it is assumed that the BFD session will follow the behavior specified in .
'desired-min-tx-interval':: The minimum interval, in microseconds, to use when transmitting BFD Control packets, less any jitter applied.
'required-min-rx-interval':: The minimum interval, in microseconds, between received BFD Control packets less any jitter applied by the sender.
'local-multiplier':: The negotiated transmit interval, multiplied by this value, provides the detection time for the peer.
'holdtime':: Used to indicate the expected BFD holddown time, in milliseconds.
'authentication':: Includes the required information to enable the BFD authentication modes discussed in . In particular, 'meticulous' controls the activation of meticulous mode as discussed in Sections 6.7.3 and 6.7.4 of .
'status':: Indicates the status of BFD.

Security The security subtree structure is shown in . The 'security' container specifies the authentication and the encryption to be applied to traffic for a given AC. Tthe model can be used to directly control the encryption to be applied (e.g., Layer 2 or Layer 3 encryption) or invoke a local encryption profile.

Security Tree Structure /nw:networks/network/network-id | +--:(customer-profile) | +--rw customer-key-chain? key-chain:key-chain-ref +--rw service ... ]]>

Service The service subtree structure is shown in .

Service Tree Structure /nw:networks/network/network-id | +--rw direction? identityref +--rw access-control-list +--rw acl-profiles +--rw acl-profile* [forwarding-profile-ref] +--rw forwarding-profile-ref leafref +--rw network-ref? -> /nw:networks/network/network-id ]]> The description of the service data nodes is as follows:

'mtu':

Specifies the Layer 2 MTU, in bytes, for the AC.

'svc-pe-to-ce-bandwidth' and 'svc-ce-to-pe-bandwidth':

Specify the service bandwidth for the AC.

'svc-pe-to-ce-bandwidth' indicates the inbound bandwidth of the connection (i.e., download bandwidth from the service provider to the site).

'svc-ce-to-pe-bandwidth' indicates the outbound bandwidth of the connection (i.e., upload bandwidth from the site to the service provider).

'svc-pe-to-ce-bandwidth' and 'svc-ce-to-pe-bandwidth' can be represented using the Committed Information Rate (CIR), the Excess Information Rate (EIR), or the Peak Information Rate (PIR).

The following types, defined in , can be used to indicate the bandwidth type:

'bw-per-cos':: The bandwidth is per CoS.
'bw-per-port':: The bandwidth is per port.
'bw-per-site':: The bandwidth is to all peer SAPs that belong to the same site.
'bw-per-service':: The bandwidth is per service instance that is bound to an AC.

'qos':

Specifies a list of QoS profiles to apply for this AC.

'access-control-list':

Specifies a list of ACL profiles to apply for this AC.

YANG Module This module uses types defined in , , , , , , , and . file "ietf-ac-ntw@2022-11-30.yang" module ietf-ac-ntw { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ac-ntw"; prefix ac-ntw; import ietf-vpn-common { prefix vpn-common; reference "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3 VPNs"; } import ietf-inet-types { prefix inet; reference "RFC 6991: Common YANG Data Types, Section 4"; } import ietf-key-chain { prefix key-chain; reference "RFC 8177: YANG Data Model for Key Chains"; } import ietf-routing-types { prefix rt-types; reference "RFC 8294: Common YANG Data Types for the Routing Area"; } import ietf-routing-policy { prefix rt-pol; reference "RFC 9067: A YANG Data Model for Routing Policy"; } import ietf-interfaces { prefix if; reference "RFC 8343: A YANG Data Model for Interface Management"; } import ieee802-dot1q-types { prefix dot1q-types; reference "IEEE Std 802.1Qcp: Bridges and Bridged Networks-- Amendment 30: YANG Data Model"; } import ietf-network { prefix nw; reference "RFC 8345: A YANG Data Model for Network Topologies, Section 6.1"; } import ietf-sap-ntw { prefix sap; reference "RFC 9408: A YANG Network Model for Service Attachment Points (SAPs)"; } import ietf-ac-common { prefix ac-common; reference "RFC CCCC: A Common YANG Data Model for Attachment Circuits"; } import ietf-ac-svc { prefix ac-svc; reference "RFC SSSS: YANG Data Models for Bearers and 'Attachment Circuits'-as-a-Service (ACaaS)"; } organization "IETF OPSAWG (Operations and Management Area Working Group)"; contact "WG Web: WG List: Editor: Mohamed Boucadair Author: Richard Roberts Author: Oscar Gonzalez de Dios Author: Samier Barguil Author: Bo Wu "; description "This YANG module defines a YANG network model for the management of attachment circuits. Copyright (c) 2024 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Revised BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX; see the RFC itself for full legal notices."; revision 2023-11-13 { description "Initial revision."; reference "RFC XXXX: A YANG Network Data Model for Attachment Circuits"; } // References /* A set of groupings to ease referencing cross-modules */ grouping attachment-circuit-reference { description "This grouping can be used to reference an attachment circuit in a specific node."; leaf ac-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]/nw:node[nw:node-id=current()/../" + "node-ref]/ac-ntw:ac/ac-ntw:name"; require-instance false; } description "A type for an absolute reference to an attachment circuit."; } uses nw:node-ref; } grouping ac-profile-reference { description "This grouping can be used to reference an attachment circuit profile."; leaf ac-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]/ac-ntw:ac-profile/ac-ntw:name"; require-instance false; } description "A type for an absolute reference to an attachment circuit."; } uses nw:network-ref; } grouping encryption-profile-reference { description "This grouping can be used to reference encryption profile."; leaf encryption-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]" + "/ac-ntw:specific-provisioning-profiles" + "/ac-ntw:valid-provider-identifiers" + "/ac-ntw:encryption-profile-identifier/ac-ntw:id"; require-instance false; } description "A type for an absolute reference to an encryption profile."; } uses nw:network-ref; } grouping qos-profile-reference { description "This grouping can be used to reference a QoS profile."; leaf qos-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]" + "/ac-ntw:specific-provisioning-profiles" + "/ac-ntw:valid-provider-identifiers" + "/ac-ntw:qos-profile-identifier/ac-ntw:id"; require-instance false; } description "A type for an absolute reference to a QoS profile."; } uses nw:network-ref; } grouping bfd-profile-reference { description "This grouping can be used to reference a BFD profile."; leaf bfd-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]" + "/ac-ntw:specific-provisioning-profiles" + "/ac-ntw:valid-provider-identifiers" + "/ac-ntw:bfd-profile-identifier/ac-ntw:id"; require-instance false; } description "A type for an absolute reference to a BFD profile."; } uses nw:network-ref; } grouping forwarding-profile-reference { description "This grouping can be used to reference a forwarding profile."; leaf forwarding-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]" + "/ac-ntw:specific-provisioning-profiles" + "/ac-ntw:valid-provider-identifiers" + "/ac-ntw:forwarding-profile-identifier/ac-ntw:id"; require-instance false; } description "A type for an absolute reference to a forwarding profile."; } uses nw:network-ref; } grouping routing-profile-reference { description "This grouping can be used to reference a routing profile."; leaf routing-profile-ref { type leafref { path "/nw:networks/nw:network[nw:network-id=current()/../" + "network-ref]" + "/ac-ntw:specific-provisioning-profiles" + "/ac-ntw:valid-provider-identifiers" + "/ac-ntw:routing-profile-identifier/ac-ntw:id"; require-instance false; } description "A type for an absolute reference to a routing profile."; } uses nw:network-ref; } // L2 conenction grouping l2-connection { description "Defines Layer 2 protocols and parameters that are required to enable AC connectivity."; container encapsulation { description "Container for Layer 2 encapsulation."; leaf encap-type { type identityref { base vpn-common:encapsulation-type; } description "Tagged interface type."; } container dot1q { when "derived-from-or-self(../encap-type, " + "'vpn-common:dot1q')" { description "Only applies when the type of the tagged interface is 'dot1q'."; } description "Tagged interface."; uses ac-common:dot1q; container tag-operations { description "Sets the tag manipulation policy for this AC. It defines a set of tag manipulations that allow for the insertion, removal, or rewriting of 802.1Q VLAN tags. These operations are indicated for the CE-PE direction. By default, tag operations are symmetric. As such, the reverse tag operation is assumed on the PE-CE direction."; choice op-choice { description "Selects the tag rewriting policy for an AC."; leaf pop { type empty; description "Pop the outer tag."; } leaf push { type empty; description "Pushes one or two tags defined by the tag-1 and tag-2 leaves. It is assumed that, absent any policy, the default value of 0 will be used for the PCP setting."; } leaf translate { type empty; description "Translates the outer tag to one or two tags. PCP bits are preserved."; } } leaf tag-1 { when 'not(../pop)'; type dot1q-types:vlanid; description "A first tag to be used for push or translate operations. This tag will be used as the outermost tag as a result of the tag operation."; } leaf tag-1-type { type dot1q-types:dot1q-tag-type; default "dot1q-types:s-vlan"; description "Specifies a specific 802.1Q tag type of tag-1."; } leaf tag-2 { when '(../translate)'; type dot1q-types:vlanid; description "A second tag to be used for translation."; } leaf tag-2-type { type dot1q-types:dot1q-tag-type; default "dot1q-types:c-vlan"; description "Specifies a specific 802.1Q tag type of tag-2."; } } } container priority-tagged { when "derived-from-or-self(../encap-type, " + "'vpn-common:priority-tagged')" { description "Only applies when the type of the tagged interface is 'priority-tagged'."; } description "Priority tagged container."; uses ac-common:priority-tagged; } container qinq { when "derived-from-or-self(../encap-type, " + "'vpn-common:qinq')" { description "Only applies when the type of the tagged interface is 'QinQ'."; } description "Includes QinQ parameters."; uses ac-common:qinq; container tag-operations { description "Sets the tag manipulation policy for this AC. It defines a set of tag manipulations that allow for the insertion, removal, or rewriting of 802.1Q VLAN tags. These operations are indicated for the CE-PE direction. By default, tag operations are symmetric. As such, the reverse tag operation is assumed on the PE-CE direction."; choice op-choice { description "Selects the tag rewriting policy for a AC."; leaf pop { type uint8 { range "1|2"; } description "Pops one or two tags as a function of the indicated pop value."; } leaf push { type empty; description "Pushes one or two tags defined by the tag-1 and tag-2 leaves. It is assumed that, absent any policy, the default value of 0 will be used for PCP setting."; } leaf translate { type uint8 { range "1|2"; } description "Translates one or two outer tags. PCP bits are preserved. The following operations are supported: - translate 1 with tag-1 leaf is provided: only the outermost tag is translated to the value in tag-1. - translate 2 with both tag-1 and tag-2 leaves are provided: both outer and inner tags are translated to the values in tag-1 and tag-2, respectively. - translate 2 with tag-1 leaf is provided: the outer tag is popped while the inner tag is translated to the value in tag-1."; } } leaf tag-1 { when 'not(../pop)'; type dot1q-types:vlanid; description "A first tag to be used for push or translate operations. This tag will be used as the outermost tag as a result of the tag operation."; } leaf tag-1-type { type dot1q-types:dot1q-tag-type; default "dot1q-types:s-vlan"; description "Specifies a specific 802.1Q tag type of tag-1."; } leaf tag-2 { when 'not(../pop)'; type dot1q-types:vlanid; description "A second tag to be used for push or translate operations."; } leaf tag-2-type { type dot1q-types:dot1q-tag-type; default "dot1q-types:c-vlan"; description "Specifies a specific 802.1Q tag type of tag-2."; } } } } choice l2-service { description "The Layer 2 connectivity service can be provided by indicating a pointer to an L2VPN or by specifying a Layer 2 tunnel service."; container l2-tunnel-service { description "Defines a Layer 2 tunnel termination."; uses ac-common:l2-tunnel-service; } case l2vpn { leaf l2vpn-id { type vpn-common:vpn-id; description "Indicates the L2VPN service associated with an Integrated Routing and Bridging (IRB) interface."; } } } } grouping l2-connection-if-ref { description "Specifies Layer 2 connection paramters with interface references."; uses l2-connection; leaf l2-termination-point { type string; description "Specifies a reference to a local Layer 2 termination point, such as a Layer 2 sub-interface."; } leaf local-bridge-reference { type string; description "Specifies a local bridge reference to accommodate, e.g., implementations that require internal bridging. A reference may be a local bridge domain."; } leaf bearer-reference { if-feature "vpn-common:bearer-reference"; type string; description "This is an internal reference for the service provider to identify the bearer associated with this AC."; } container lag-interface { if-feature "vpn-common:lag-interface"; description "Container for configuration of Link Aggregation Group (LAG) interface attributes."; leaf lag-interface-id { type string; description "LAG interface identifier."; } container member-link-list { description "Container for the member link list."; list member-link { key "name"; description "Member link."; leaf name { type string; description "Member link name."; } } } } } // IPv4 connection groupings grouping ipv4-connection { description "IPv4-specific parameters."; leaf local-address { type inet:ipv4-address; description "The IP address used at the provider's interface."; } uses ac-common:ipv4-allocation-type; choice allocation-type { description "Choice of the IPv4 address allocation."; case dynamic { description "When the addresses are allocated by DHCP or other dynamic means local to the infrastructure."; choice address-assign { description "A choice for how IPv4 addresses are assigned."; case number { leaf number-of-dynamic-address { type uint16; description "Specifies the number of IP addresses to be assigned to the customer on this access."; } } case explicit { container customer-addresses { description "Container for customer addresses to be allocated using DHCP."; list address-pool { key "pool-id"; description "Describes IP addresses to be dyncamically allocated. When only 'start-address' is present, it represents a single address. When both 'start-address' and 'end-address' are specified, it implies a range inclusive of both addresses."; leaf pool-id { type string; description "A pool identifier for the address range from 'start-address' to 'end-address'."; } leaf start-address { type inet:ipv4-address; mandatory true; description "Indicates the first address in the pool."; } leaf end-address { type inet:ipv4-address; description "Indicates the last address in the pool."; } } } } } choice provider-dhcp { description "Parameters related to DHCP-allocated addresses. IP addresses are allocated by DHCP, which is provided by the operator."; leaf dhcp-service-type { type enumeration { enum server { description "Local DHCP server."; } enum relay { description "Local DHCP relay. DHCP requests are relayed to a provider's server."; } } description "Indicates the type of DHCP service to be enabled on this access."; } choice service-type { description "Choice based on the DHCP service type."; case relay { description "Container for a list of the provider's DHCP servers (i.e., 'dhcp-service-type' is set to 'relay')."; leaf-list server-ip-address { type inet:ipv4-address; description "IPv4 addresses of the provider's DHCP server, for use by the local DHCP relay."; } } } } choice dhcp-relay { description "The DHCP relay is provided by the operator."; container customer-dhcp-servers { description "Container for a list of the customer's DHCP servers."; leaf-list server-ip-address { type inet:ipv4-address; description "IPv4 addresses of the customer's DHCP server."; } } } } case static-addresses { description "Lists the IPv4 addresses that are used."; list address { key "address-id"; ordered-by user; description "Lists the IPv4 addresses that are used. The first address of the list is the primary address of the connection."; leaf address-id { type string; description "An identifier of the static IPv4 address."; } leaf customer-address { type inet:ipv4-address; description "An IPv4 address of the customer side."; } } } } } grouping ipv6-connection { description "IPv6-specific parameters."; leaf local-address { type inet:ipv6-address; description "IPv6 address of the provider side."; } uses ac-common:ipv6-allocation-type; choice allocation-type { description "Choice of the IPv6 address allocation."; case dynamic { description "When the addresses are allocated by DHCP or other dynamic means local to the infrastructure."; choice address-assign { description "A choice for how IPv6 addresses are assigned."; case number { leaf number-of-dynamic-address { type uint16; description "Specifies the number of IP addresses to be assigned to the customer on this access."; } } case explicit { container customer-addresses { description "Container for customer addresses to be allocated using DHCP."; list address-pool { key "pool-id"; description "Describes IP addresses to be dyncamically allocated. When only 'start-address' is present, it represents a single address. When both 'start-address' and 'end-address' are specified, it implies a range inclusive of both addresses."; leaf pool-id { type string; description "A pool identifier for the address range from 'start-address' to 'end-address'."; } leaf start-address { type inet:ipv6-address; mandatory true; description "Indicates the first address in the pool."; } leaf end-address { type inet:ipv6-address; description "Indicates the last address in the pool."; } } } } } choice provider-dhcp { description "Parameters related to DHCP-allocated addresses. IP addresses are allocated by DHCP, which is provided by the operator."; leaf dhcp-service-type { type enumeration { enum server { description "Local DHCP server."; } enum relay { description "Local DHCP relay. DHCP requests are relayed to a provider's server."; } } description "Indicates the type of DHCP service to be enabled on this access."; } choice service-type { description "Choice based on the DHCP service type."; case relay { description "Container for a list of the provider's DHCP servers (i.e., 'dhcp-service-type' is set to 'relay')."; leaf-list server-ip-address { type inet:ipv6-address; description "IPv6 addresses of the provider's DHCP server, for use by the local DHCP relay."; } } } } choice dhcp-relay { description "The DHCP relay is provided by the operator."; container customer-dhcp-servers { description "Container for a list of the customer's DHCP servers."; leaf-list server-ip-address { type inet:ipv6-address; description "IPv6 addresses of the customer's DHCP server."; } } } } case static-addresses { description "Lists the IPv4 addresses that are used."; list address { key "address-id"; ordered-by user; description "Lists the IPv6 addresses that are used. The first address of the list is the primary address of the connection."; leaf address-id { type string; description "An identifier of the static IPv4 address."; } leaf customer-address { type inet:ipv6-address; description "An IPv6 address of the customer side."; } } } } } grouping ip-connection { description "Defines IP connection parameters."; leaf l3-termination-point { type string; description "Specifies a reference to a local Layer 3 termination point, such as a bridge domain interface."; } container ipv4 { if-feature "vpn-common:ipv4"; description "IPv4-specific parameters."; uses ipv4-connection; } container ipv6 { if-feature "vpn-common:ipv6"; description "IPv6-specific parameters."; uses ipv6-connection; } } /* Routing */ //BGP base parameters grouping bgp-base { description "Configuration specific to BGP."; leaf description { type string; description "Includes a description of the BGP session. This description is meant to be used for diagnostic purposes. The semantic of the description is local to an implementation."; } uses rt-pol:apply-policy-group; leaf local-as { type inet:as-number; description "Indicates a local AS Number (ASN), if an ASN distinct from the ASN configured at the AC level is needed."; } leaf peer-as { type inet:as-number; mandatory true; description "Indicates the customer's ASN when the customer requests BGP routing."; } leaf address-family { type identityref { base vpn-common:address-family; } description "This node contains the address families to be activated. 'dual-stack' means that both IPv4 and IPv6 will be activated."; } leaf multihop { type uint8; description "Describes the number of IP hops allowed between a given BGP neighbor and the PE."; } leaf as-override { type boolean; description "Defines whether ASN override is enabled, i.e., replacing the ASN of the customer specified in the AS_PATH attribute with the local ASN."; } leaf allow-own-as { type uint8; description "If set, specifies the maximum number of occurrences of the provider's ASN that are permitted within the AS_PATH before it is rejected."; } leaf prepend-global-as { type boolean; description "In some situations, the ASN that is provided at the node level may be distinct from the ASN configured at the AC. When such ASNs are provided, they are both prepended to the BGP route updates for this AC. To disable that behavior, 'prepend-global-as' must be set to 'false'. In such a case, the ASN that is provided at the node level is not prepended to the BGP route updates for this access."; } leaf send-default-route { type boolean; description "Defines whether default routes can be advertised to a peer. If set, the default routes are advertised to a peer."; } leaf site-of-origin { when "derived-from-or-self(../address-family, " + "'vpn-common:ipv4' or 'vpn-common:dual-stack')" { description "Only applies if IPv4 is activated."; } type rt-types:route-origin; description "The Site of Origin attribute is encoded as a Route Origin Extended Community. It is meant to uniquely identify the set of routes learned from a site via a particular AC and is used to prevent routing loops."; reference "RFC 4364: BGP/MPLS IP Virtual Private Networks (VPNs), Section 7"; } leaf ipv6-site-of-origin { when "derived-from-or-self(../address-family, " + "'vpn-common:ipv6' or 'vpn-common:dual-stack')" { description "Only applies if IPv6 is activated."; } type rt-types:ipv6-route-origin; description "The IPv6 Site of Origin attribute is encoded as an IPv6 Route Origin Extended Community. It is meant to uniquely identify the set of routes learned from a site."; reference "RFC 5701: IPv6 Address Specific BGP Extended Community Attribute"; } list redistribute-connected { key "address-family"; description "Indicates, per address family, the policy to follow for connected routes."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates the address family."; } leaf enabled { type boolean; description "Enables the redistribution of connected routes."; } } container bgp-max-prefix { description "Controls the behavior when a prefix maximum is reached."; leaf max-prefix { type uint32; description "Indicates the maximum number of BGP prefixes allowed in the BGP session. It allows control of how many prefixes can be received from a neighbor. If the limit is exceeded, the action indicated in 'violate-action' will be followed."; reference "RFC 4271: A Border Gateway Protocol 4 (BGP-4), Section 8.2.2"; } leaf warning-threshold { type decimal64 { fraction-digits 5; range "0..100"; } units "percent"; description "When this value is reached, a warning notification will be triggered."; } leaf violate-action { type enumeration { enum warning { description "Only a warning message is sent to the peer when the limit is exceeded."; } enum discard-extra-paths { description "Discards extra paths when the limit is exceeded."; } enum restart { description "The BGP session restarts after the indicated time interval."; } } description "If the BGP neighbor 'max-prefix' limit is reached, the action indicated in 'violate-action' will be followed."; } leaf restart-timer { type uint32; units "seconds"; description "Time interval after which the BGP session will be reestablished."; } } container bgp-timers { description "Includes two BGP timers."; leaf keepalive { type uint16 { range "0..21845"; } units "seconds"; description "This timer indicates the KEEPALIVE messages' frequency between a PE and a BGP peer. If set to '0', it indicates that KEEPALIVE messages are disabled. It is suggested that the maximum time between KEEPALIVE messages be one-third of the Hold Time interval."; reference "RFC 4271: A Border Gateway Protocol 4 (BGP-4), Section 4.4"; } leaf hold-time { type uint16 { range "0 | 3..65535"; } units "seconds"; description "Indicates the maximum number of seconds that may elapse between the receipt of successive KEEPALIVE and/or UPDATE messages from the peer. The Hold Time must be either zero or at least three seconds."; reference "RFC 4271: A Border Gateway Protocol 4 (BGP-4), Section 4.2"; } } list capability { key "address-family"; description "Customized set of BGP capabilities per address family."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates the address family."; } leaf name { type identityref { base ac-common:bgp-capability; } mandatory true; description "Indicates the name of BGP capability."; } } } // RIP base parameters grouping rip-base { description "Configuration specific to RIP routing."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be activated."; } container timers { description "Indicates the RIP timers."; reference "RFC 2453: RIP Version 2"; leaf update-interval { type uint16 { range "1..32767"; } units "seconds"; description "Indicates the RIP update time, i.e., the amount of time for which RIP updates are sent."; } leaf invalid-interval { type uint16 { range "1..32767"; } units "seconds"; description "The interval before a route is declared invalid after no updates are received. This value is at least three times the value for the 'update-interval' argument."; } leaf holddown-interval { type uint16 { range "1..32767"; } units "seconds"; description "Specifies the interval before better routes are released."; } leaf flush-interval { type uint16 { range "1..32767"; } units "seconds"; description "Indicates the RIP flush timer, i.e., the amount of time that must elapse before a route is removed from the routing table."; } } leaf default-metric { type uint8 { range "0..16"; } description "Sets the default metric."; } } // routing profile grouping routing-profile { description "Defines routing protocols."; list routing-protocol { key "id"; description "List of routing protocols used on the AC."; leaf id { type string; description "Unique identifier for the routing protocol."; } leaf type { type identityref { base vpn-common:routing-protocol-type; } description "Type of routing protocol."; } container bgp { when "derived-from-or-self(../type, " + "'vpn-common:bgp-routing')" { description "Only applies when the protocol is BGP."; } description "Configuration specific to BGP."; uses bgp-base; } container ospf { when "derived-from-or-self(../type, " + "'vpn-common:ospf-routing')" { description "Only applies when the protocol is OSPF."; } description "Configuration specific to OSPF."; uses ac-common:ospf-basic; leaf max-lsa { type uint32 { range "1..4294967294"; } description "Maximum number of allowed Link State Advertisements (LSAs) that the OSPF instance will accept."; } } container isis { when "derived-from-or-self(../type, " + "'vpn-common:isis-routing')" { description "Only applies when the protocol is IS-IS."; } description "Configuration specific to IS-IS."; uses ac-common:isis-basic; leaf level { type identityref { base vpn-common:isis-level; } description "Can be 'level-1', 'level-2', or 'level-1-2'."; reference "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3 VPNs"; } leaf metric { type uint16; description "Metric of the AC. It is used in the routing state calculation and path selection."; } leaf mode { type enumeration { enum active { description "The interface sends or receives IS-IS protocol control packets."; } enum passive { description "Suppresses the sending of IS-IS updates through the specified interface."; } } description "IS-IS interface mode type."; } } container rip { when "derived-from-or-self(../type, " + "'vpn-common:rip-routing')" { description "Only applies when the protocol is RIP."; } description "Configuration specific to RIP routing."; uses rip-base; } container vrrp { when "derived-from-or-self(../type, " + "'vpn-common:vrrp-routing')" { description "Only applies when the protocol is the Virtual Router Redundancy Protocol (VRRP)."; } description "Configuration specific to VRRP."; reference "RFC 5798: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6"; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be enabled."; } leaf ping-reply { type boolean; description "Controls whether the VRRP speaker should reply to ping requests."; } } } } grouping routing { description "Defines routing protocols."; list routing-protocol { key "id"; description "List of routing protocols used on the AC."; leaf id { type string; description "Unique identifier for the routing protocol."; } leaf type { type identityref { base vpn-common:routing-protocol-type; } description "Type of routing protocol."; } list routing-profile { key "routing-profile-ref"; description "Routing profiles."; uses routing-profile-reference; leaf type { type identityref { base vpn-common:ie-type; } description "Import, export, or both."; } } container static { when "derived-from-or-self(../type, " + "'vpn-common:static-routing')" { description "Only applies when the protocol is a static routing protocol."; } description "Configuration specific to static routing."; container cascaded-lan-prefixes { description "LAN prefixes from the customer."; list ipv4-lan-prefix { if-feature "vpn-common:ipv4"; key "lan next-hop"; description "List of LAN prefixes for the site."; uses ac-common:ipv4-static-rtg-entry; uses bfd-routing; leaf preference { type uint32; description "Indicates the preference associated with the static route."; } uses ac-common:service-status; } list ipv6-lan-prefix { if-feature "vpn-common:ipv6"; key "lan next-hop"; description "List of LAN prefixes for the site."; uses ac-common:ipv4-static-rtg-entry; uses bfd-routing; leaf preference { type uint32; description "Indicates the preference associated with the static route."; } uses ac-common:service-status; } } } container bgp { when "derived-from-or-self(../type, " + "'vpn-common:bgp-routing')" { description "Only applies when the protocol is BGP."; } description "Configuration specific to BGP."; container peer-groups { description "Configuration for BGP peer-groups"; list peer-group { key "name"; description "List of BGP peer-groups configured on the local system - uniquely identified by peer-group name"; leaf name { type string; description "Name of the BGP peer-group"; } leaf local-address { type union { type inet:ip-address; type if:interface-ref; } description "Sets the local IP address to use for the BGP transport session. This may be expressed as either an IP address or a reference to an interface."; } uses bgp-base; uses ac-common:bgp-authentication; } } list neighbor { key "remote-address"; description "List of BGP neighbors."; leaf remote-address { type inet:ip-address; description "The remote IP address of this entry's BGP peer."; } leaf local-address { type union { type inet:ip-address; type if:interface-ref; } description "Sets the local IP address to use for the BGP transport session. This may be expressed as either an IP address or a reference to an interface."; } leaf peer-group { type leafref { path "../../peer-groups/peer-group/name"; } description "The peer-group with which this neighbor is associated."; } uses bgp-base; uses bfd-routing; uses ac-common:bgp-authentication; uses ac-common:service-status; } } container ospf { when "derived-from-or-self(../type, " + "'vpn-common:ospf-routing')" { description "Only applies when the protocol is OSPF."; } description "Configuration specific to OSPF."; uses ac-common:ospf-basic; container sham-links { if-feature "vpn-common:rtg-ospf-sham-link"; description "List of sham links."; reference "RFC 4577: OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private Networks (VPNs), Section 4.2.7 RFC 6565: OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol, Section 5"; list sham-link { key "target-site"; description "Creates a sham link with another site."; leaf target-site { type string; description "Target site for the sham link connection. The site is referred to by its identifier."; } leaf metric { type uint16; description "Metric of the sham link. It is used in the routing state calculation and path selection."; reference "RFC 4577: OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private Networks (VPNs), Section 4.2.7.3 RFC 6565: OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol, Section 5.2"; } } } leaf max-lsa { type uint32 { range "1..4294967294"; } description "Maximum number of allowed Link State Advertisements (LSAs) that the OSPF instance will accept."; } uses ac-common:ospf-authentication; uses ac-common:service-status; } container isis { when "derived-from-or-self(../type, " + "'vpn-common:isis-routing')" { description "Only applies when the protocol is IS-IS."; } description "Configuration specific to IS-IS."; uses ac-common:isis-basic; leaf level { type identityref { base vpn-common:isis-level; } description "Can be 'level-1', 'level-2', or 'level-1-2'."; reference "RFC 9181: A Common YANG Data Model for Layer 2 and Layer 3 VPNs"; } leaf metric { type uint16; description "Metric of the PE-CE link. It is used in the routing state calculation and path selection."; } leaf mode { type enumeration { enum active { description "The interface sends or receives IS-IS protocol control packets."; } enum passive { description "Suppresses the sending of IS-IS updates through the specified interface."; } } description "IS-IS interface mode type."; } uses ac-common:isis-authentication; uses ac-common:service-status; } container rip { when "derived-from-or-self(../type, " + "'vpn-common:rip-routing')" { description "Only applies when the protocol is RIP. For IPv4, the model assumes that RIP version 2 is used."; } description "Configuration specific to RIP routing."; uses rip-base; uses ac-common:rip-authentication; uses ac-common:service-status; } container vrrp { when "derived-from-or-self(../type, " + "'vpn-common:vrrp-routing')" { description "Only applies when the protocol is the VRRP."; } description "Configuration specific to VRRP."; reference "RFC 5798: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6"; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both address families are to be enabled."; } leaf vrrp-group { type uint8 { range "1..255"; } description "Includes the VRRP group identifier."; } leaf backup-peer { type inet:ip-address; description "Indicates the IP address of the peer."; } leaf-list virtual-ip-address { type inet:ip-address; description "Virtual IP addresses for a single VRRP group."; reference "RFC 5798: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6, Sections 1.2 and 1.3"; } leaf priority { type uint8 { range "1..254"; } description "Sets the local priority of the VRRP speaker."; } leaf ping-reply { type boolean; description "Controls whether the VRRP speaker should reply to ping requests."; } uses ac-common:service-status; } } } // OAM grouping bfd { description "Grouping for BFD."; leaf session-type { type identityref { base vpn-common:bfd-session-type; } description "Specifies the BFD session type."; } leaf desired-min-tx-interval { type uint32; units "microseconds"; description "The minimum interval between transmissions of BFD Control packets, as desired by the operator."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.8.7"; } leaf required-min-rx-interval { type uint32; units "microseconds"; description "The minimum interval between received BFD Control packets that the PE should support."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.8.7"; } leaf local-multiplier { type uint8 { range "1..255"; } description "Specifies the detection multiplier that is transmitted to a BFD peer. The detection interval for the receiving BFD peer is calculated by multiplying the value of the negotiated transmission interval by the received detection multiplier value."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.8.7"; } leaf holdtime { type uint32; units "milliseconds"; description "Expected BFD holdtime. The customer may impose some fixed values for the holdtime period if the provider allows the customer to use this function."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.8.18"; } } grouping bfd-routing { description "Defines a basic BFD grouping for routing configuration."; container bfd { description "BFD control for this nighbor."; leaf enable { type boolean; description "Enables BFD if set to true. BFD is disabled of set to false."; } uses bfd-profile-reference; } } // OAM grouping oam { description "Defines the Operations, Administration, and Maintenance (OAM) mechanisms used."; container bfd { description "Container for BFD."; list session { key "dest-addr"; description "List of IP sessions."; leaf dest-addr { type inet:ip-address; description "IP address of the peer."; } leaf source-address { type union { type inet:ip-address; type if:interface-ref; } description "Sets the local IP address to use for the BFD session. This may be expressed as either an IP address or a reference to an interface."; } uses bfd-profile-reference; uses bfd; container authentication { presence "Enables BFD authentication"; description "Parameters for BFD authentication."; leaf key-chain { type key-chain:key-chain-ref; description "Name of the key chain."; } leaf meticulous { type boolean; description "Enables meticulous mode."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.7"; } } uses ac-common:service-status; } } } // security grouping security { description "Security parameters for an AC."; container encryption { if-feature "vpn-common:encryption"; description "Container for AC encryption."; leaf enabled { type boolean; description "If set to 'true', traffic encryption on the connection is required. Otherwise, it is disabled."; } leaf layer { when "../enabled = 'true'" { description "Included only when encryption is enabled."; } type enumeration { enum layer2 { description "Encryption occurs at Layer 2."; } enum layer3 { description "Encryption occurs at Layer 3. For example, IPsec may be used when a customer requests Layer 3 encryption."; } } description "Indicates the layer on which encryption is applied."; } } container encryption-profile { when "../encryption/enabled = 'true'" { description "Indicates the layer on which encryption is enabled."; } description "Container for the encryption profile."; choice profile { description "Choice for the encryption profile."; case provider-profile { uses encryption-profile-reference; } case customer-profile { leaf customer-key-chain { type key-chain:key-chain-ref; description "Customer-supplied key chain."; } } } } } // AC profile grouping ac-profile { description "Grouping for attachment circuit profiles."; container routing-protocols { description "Defines routing protocols."; uses routing-profile; } container oam { description "Defines the OAM mechanisms used for the AC profile."; container bfd { if-feature "vpn-common:bfd"; description "Container for BFD."; uses bfd; } } } // AC network provisioning grouping ac { description "Grouping for attachment circuits."; leaf description { type string; description "Associates a description with an AC."; } container l2-connection { description "Defines Layer 2 protocols and parameters that are required to enable AC connectivity."; uses l2-connection-if-ref; } container ip-connection { description "Defines IP connection parameters."; uses ip-connection; } container routing-protocols { description "Defines routing protocols."; uses routing; } container oam { description "Defines the OAM mechanisms used for the AC."; uses oam; } container security { description "AC-specific security parameters."; uses security; } container service { description "AC-specific bandwith parameters."; leaf mtu { type uint32; units "bytes"; description "Layer 2 MTU."; } uses ac-svc:bandwidth; container qos { if-feature "vpn-common:qos"; description "QoS configuration."; container qos-profiles { description "QoS profile configuration."; list qos-profile { key "qos-profile-ref"; description "Points to a QoS profile."; uses qos-profile-reference; leaf direction { type identityref { base vpn-common:qos-profile-direction; } description "The direction to which the QoS profile is applied."; } } } } container access-control-list { description "Container for the Access Control List (ACL)."; container acl-profiles { description "ACL profile configuration."; list acl-profile { key "forwarding-profile-ref"; description "Points to an ACL profile."; uses forwarding-profile-reference; } } } } } augment "/nw:networks/nw:network" { description "Add a list of profiles."; container specific-provisioning-profiles { description "Contains a set of valid profiles to reference in the AC activation."; uses ac-common:ac-profile-cfg; } list ac-profile { key "name"; description "Specifies a list of AC profiles."; leaf name { type string; description "Name of the AC."; } uses ac-ntw:ac-profile; } } augment "/nw:networks/nw:network/nw:node" { when '../nw:network-types/sap:sap-network' { description "Augmentation parameters apply only for SAP networks."; } description "Augments nodes with AC provisioning details."; list ac { key "name"; description "List of ACs."; leaf name { type string; description "A name that identifies the AC locally."; } leaf ac-svc-ref { type ac-svc:attachment-circuit-reference; description "A reference to the AC as exposed at the service level."; } list ac-profile { key "ac-profile-ref"; description "List of AC profiles."; uses ac-profile-reference; } container ac-parent-ref { description "Specifies the parent AC that is inherited by an AC. Parent ACs are used, e.g., in contexts where multiple CEs are terminating the same AC, but some specific information is required for each peer SAP."; uses ac-ntw:attachment-circuit-reference; } leaf-list peer-sap-id { type string; description "One or more peer SAPs can be indicated."; } list group { key "group-id"; description "List of group-ids."; leaf group-id { type string; description "Indicates the group-id to which the AC belongs."; } leaf precedence { type identityref { base ac-common:precedence-type; } description "Defines redundancy of an AC."; } } uses ac-common:service-status; uses ac-ntw:ac; } } augment "/nw:networks/nw:network/nw:node" + "/sap:service/sap:sap" { when '../../../nw:network-types/sap:sap-network' { description "Augmentation parameters apply only for SAP networks."; } description "Augments SAPs with AC provisioning details."; list ac { key "ac-ref"; description "Specifies the ACs that are terminated by the SAP."; uses ac-ntw:attachment-circuit-reference; } } }

]]>


    
      Security Considerations
      This section uses the template described in Section 3.7 of .
      The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF  or RESTCONF .  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) .  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   .
      The Network Configuration Access Control Model (NACM) 
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.
      There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive or vulnerable
   in some network environments.  Write operations (e.g., edit-config)
   and delete operations to these data nodes without proper protection
   or authentication can have a negative effect on network operations.
   Specifically, the following
subtrees and data nodes have particular sensitivities/vulnerabilities:
      
        'specific-provisioning-profiles':
        
          This container includes a set of sensitive data that
 influence how an AC is delivered.  For example, an
 attacker who has access to these data nodes may be able to
 manipulate routing policies, QoS policies, or encryption
 properties. These data nodes are defined with "nacm:default-deny-
 write" tagging .
        
        'ac':
        
          An attacker who is able to access network nodes can
 undertake various attacks, such as modify the attributes of an AC (e.g.,
 QoS, bandwidth, routing protocols, keying material), leading to
 malfunctioning of services that are delivered over that AC and therefore to Service Level
 Agreement (SLA) violations.  In addition, an attacker could
 attempt to add a new AC.
    : In addition to using NACM to prevent unauthorized access, such
 activity can be detected by adequately monitoring and tracking
 network configuration changes.
        
      
      Some of the readable data nodes in this YANG module may be considered
   sensitive or vulnerable in some network environments.  It is thus
   important to control read access (e.g., via get, get-config, or
   notification) to these data nodes. Specifically, the following
subtrees and data nodes have particular sensitivities/vulnerabilities:
      
        'ac':
        
          Unauthorized access to this subtree can disclose the identity
 of a customer 'peer-sap-id'.
        
        'l2-connection' and 'ip-connection':
        
          An attacker can retrieve
privacy-related information, which can be used to track a
customer.  Disclosing such information may be considered a
violation of the customer-provider trust relationship.
        
        'keying-material':
        
          An attacker can retrieve the cryptographic keys
protecting an AC (routing, in particular). These keys could
be used to inject spoofed routing  advertisements.
        
      
      Several data nodes ('bgp', 'ospf', 'isis', and 'rip') rely upon  for authentication purposes. As such, the AC network module inherits the security considerations discussed in Section 5 of . Also, these data nodes support supplying explicit keys as strings in ASCII format. The use of keys in hexadecimal string format would afford greater key entropy with the same number of key-string octets. However, such a format is not included in this version of the AC network model, because it is not supported by the underlying device modules (e.g., ).
    
    
      IANA Considerations
      IANA is requested to register the following URI in the "ns" subregistry within
   the "IETF XML Registry" :
      
      IANA is requested to register the following YANG module in the "YANG Module
   Names" subregistry  within the "YANG Parameters" registry:


  
    
      References
      
        Normative References
        
          
            IEEE Standard for Local and metropolitan area networks--Bridges and Bridged Networks--Amendment 30: YANG Data Model
            
              IEEE
            
            
          
        
        
          
            YANG Data Models for Bearers and 'Attachment Circuits'-as-a-Service (ACaaS)
            
              Orange
            
            
              Juniper
            
            
              Telefonica
            
            
              Nokia
            
            
              Huawei Technologies
            
            
            
                 This document specifies a YANG service data model for Attachment
   Circuits (ACs).  This model can be used for the provisioning of ACs
   before or during service provisioning (e.g., Network Slice Service).
   The document also specifies a service model for managing bearers over
   which ACs are established.

   Also, the document specifies a set of reusable groupings.  Whether
   other service models reuse structures defined in the AC models or
   simply include an AC reference is a design choice of these service
   models.  Utilizing the AC service model to manage ACs over which a
   service is delivered has the advantage of decoupling service
   management from upgrading AC components to incorporate recent AC
   technologies or features.

              
            
          
          
        
        
          
            A YANG Network Data Model for Layer 2 VPNs
            
            
            
            
            
            
              This document defines an L2VPN Network Model (L2NM) that can be used to manage the provisioning of Layer 2 Virtual Private Network (L2VPN) services within a network (e.g., a service provider network). The L2NM complements the L2VPN Service Model (L2SM) by providing a network-centric view of the service that is internal to a service provider. The L2NM is particularly meant to be used by a network controller to derive the configuration information that will be sent to relevant network devices.
              Also, this document defines a YANG module to manage Ethernet segments and the initial versions of two IANA-maintained modules that include a set of identities of BGP Layer 2 encapsulation types and pseudowire types.
            
          
          
          
        
        
          
            A YANG Network Data Model for Layer 3 VPNs
            
            
            
            
            
            
            
              As a complement to the Layer 3 Virtual Private Network Service Model (L3SM), which is used for communication between customers and service providers, this document defines an L3VPN Network Model (L3NM) that can be used for the provisioning of Layer 3 Virtual Private Network (L3VPN) services within a service provider network. The model provides a network-centric view of L3VPN services.
              The L3NM is meant to be used by a network controller to derive the configuration information that will be sent to relevant network devices. The model can also facilitate communication between a service orchestrator and a network controller/orchestrator.
            
          
          
          
        
        
          
            A YANG Data Model for Network Topologies
            
            
            
            
            
            
            
            
              This document defines an abstract (generic, or base) YANG data model for network/service topologies and inventories. The data model serves as a base model that is augmented with technology-specific details in other, more specific topology and inventory data models.
            
          
          
          
        
        
          
            A YANG Network Data Model for Service Attachment Points (SAPs)
            
            
            
            
            
            
            
              This document defines a YANG data model for representing an abstract view of the provider network topology that contains the points from which its services can be attached (e.g., basic connectivity, VPN, network slices). Also, the model can be used to retrieve the points where the services are actually being delivered to customers (including peer networks).
              This document augments the 'ietf-network' data model defined in RFC 8345 by adding the concept of Service Attachment Points (SAPs). The SAPs are the network reference points to which network services, such as Layer 3 Virtual Private Network (L3VPN) or Layer 2 Virtual Private Network (L2VPN), can be attached. One or multiple services can be bound to the same SAP. Both User-to-Network Interface (UNI) and Network-to-Network Interface (NNI) are supported in the SAP data model.
            
          
          
          
        
        
          
            A Common YANG Data Model for Attachment Circuits
            
              Orange
            
            
              Juniper
            
            
              Telefonica
            
            
              Nokia
            
            
              Huawei Technologies
            
            
            
                 The document specifies a common Attachment Circuits (ACs) YANG
   module, which is designed with the intent to be reusable by other
   models.  For example, this common model can be reused by service
   models to expose ACs as a service, service models that require
   binding a service to a set of ACs, network and device models to
   provision ACs, etc.

              
            
          
          
        
        
          
            Network Management Datastore Architecture (NMDA)
            
            
            
            
            
            
            
              Datastores are a fundamental concept binding the data models written in the YANG data modeling language to network management protocols such as the Network Configuration Protocol (NETCONF) and RESTCONF. This document defines an architectural framework for datastores based on the experience gained with the initial simpler model, addressing requirements that were not well supported in the initial model. This document updates RFC 7950.
            
          
          
          
        
        
          
            Key words for use in RFCs to Indicate Requirement Levels
            
            
            
              In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.
            
          
          
          
          
        
        
          
            Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words
            
            
            
              RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings.
            
          
          
          
          
        
        
          
            A Common YANG Data Model for Layer 2 and Layer 3 VPNs
            
            
            
            
            
            
              This document defines a common YANG module that is meant to be reused by various VPN-related modules such as Layer 3 VPN and Layer 2 VPN network models.
            
          
          
          
        
        
          
            Bidirectional Forwarding Detection (BFD)
            
            
            
            
              This document describes a protocol intended to detect faults in the bidirectional path between two forwarding engines, including interfaces, data link(s), and to the extent possible the forwarding engines themselves, with potentially very low latency. It operates independently of media, data protocols, and routing protocols. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)
            
            
            
            
              Layer 2 services (such as Frame Relay, Asynchronous Transfer Mode, and Ethernet) can be emulated over an MPLS backbone by encapsulating the Layer 2 Protocol Data Units (PDUs) and then transmitting them over pseudowires (PWs). It is also possible to use pseudowires to provide low-rate Time-Division Multiplexed and Synchronous Optical NETworking circuit emulation over an MPLS-enabled network. This document specifies a protocol for establishing and maintaining the pseudowires, using extensions to the Label Distribution Protocol (LDP). Procedures for encapsulating Layer 2 PDUs are specified in other documents.
              This document is a rewrite of RFC 4447 for publication as an Internet Standard.
            
          
          
          
          
        
        
          
            A YANG Data Model for Routing Policy
            
            
            
            
            
            
              This document defines a YANG data model for configuring and managing routing policies in a vendor-neutral way. The model provides a generic routing policy framework that can be extended for specific routing protocols using the YANG 'augment' mechanism.
            
          
          
          
        
        
          
            BGP/MPLS IP Virtual Private Networks (VPNs)
            
            
            
            
              This document describes a method by which a Service Provider may use an IP backbone to provide IP Virtual Private Networks (VPNs) for its customers. This method uses a "peer model", in which the customers' edge routers (CE routers) send their routes to the Service Provider's edge routers (PE routers); there is no "overlay" visible to the customer's routing algorithm, and CE routers at different sites do not peer with each other. Data packets are tunneled through the backbone, so that the core routers do not need to know the VPN routes. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            IPv6 Address Specific BGP Extended Community Attribute
            
            
            
              Current specifications of BGP Extended Communities (RFC 4360) support the IPv4 Address Specific Extended Community, but do not support an IPv6 Address Specific Extended Community. The lack of an IPv6 Address Specific Extended Community may be a problem when an application uses the IPv4 Address Specific Extended Community, and one wants to use this application in a pure IPv6 environment. This document defines a new BGP attribute, the IPv6 Address Specific Extended Community, that addresses this problem. The IPv6 Address Specific Extended Community is similar to the IPv4 Address Specific Extended Community, except that it carries an IPv6 address rather than an IPv4 address. [STANDARDS TRACK]
            
          
          
          
        
        
          
            A Border Gateway Protocol 4 (BGP-4)
            
            
            
            
            
              This document discusses the Border Gateway Protocol (BGP), which is an inter-Autonomous System routing protocol.
              The primary function of a BGP speaking system is to exchange network reachability information with other BGP systems. This network reachability information includes information on the list of Autonomous Systems (ASes) that reachability information traverses. This information is sufficient for constructing a graph of AS connectivity for this reachability from which routing loops may be pruned, and, at the AS level, some policy decisions may be enforced.
              BGP-4 provides a set of mechanisms for supporting Classless Inter-Domain Routing (CIDR). These mechanisms include support for advertising a set of destinations as an IP prefix, and eliminating the concept of network "class" within BGP. BGP-4 also introduces mechanisms that allow aggregation of routes, including aggregation of AS paths.
              This document obsoletes RFC 1771. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            The TCP Authentication Option
            
            
            
            
            
              This document specifies the TCP Authentication Option (TCP-AO), which obsoletes the TCP MD5 Signature option of RFC 2385 (TCP MD5). TCP-AO specifies the use of stronger Message Authentication Codes (MACs), protects against replays even for long-lived TCP connections, and provides more details on the association of security with TCP connections than TCP MD5. TCP-AO is compatible with either a static Master Key Tuple (MKT) configuration or an external, out-of-band MKT management mechanism; in either case, TCP-AO also protects connections when using the same MKT across repeated instances of a connection, using traffic keys derived from the MKT, and coordinates MKT changes between endpoints. The result is intended to support current infrastructure uses of TCP MD5, such as to protect long-lived connections (as used, e.g., in BGP and LDP), and to support a larger set of MACs with minimal other system and operational changes. TCP-AO uses a different option identifier than TCP MD5, even though TCP-AO and TCP MD5 are never permitted to be used simultaneously. TCP-AO supports IPv6, and is fully compatible with the proposed requirements for the replacement of TCP MD5. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            YANG Data Model for Key Chains
            
            
            
            
            
            
            
              This document describes the key chain YANG data model. Key chains are commonly used for routing protocol authentication and other applications requiring symmetric keys. A key chain is a list containing one or more elements containing a Key ID, key string, send/accept lifetimes, and the associated authentication or encryption algorithm. By properly overlapping the send and accept lifetimes of multiple key chain elements, key strings and algorithms may be gracefully updated. By representing them in a YANG data model, key distribution can be automated.
            
          
          
          
        
        
          
            OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private Networks (VPNs)
            
            
            
            
            
              Many Service Providers offer Virtual Private Network (VPN) services to their customers, using a technique in which customer edge routers (CE routers) are routing peers of provider edge routers (PE routers). The Border Gateway Protocol (BGP) is used to distribute the customer's routes across the provider's IP backbone network, and Multiprotocol Label Switching (MPLS) is used to tunnel customer packets across the provider's backbone. This is known as a "BGP/MPLS IP VPN". The base specification for BGP/MPLS IP VPNs presumes that the routing protocol on the interface between a PE router and a CE router is BGP. This document extends that specification by allowing the routing protocol on the PE/CE interface to be the Open Shortest Path First (OSPF) protocol.
              This document updates RFC 4364. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol
            
            
            
            
            
            
            
              Many Service Providers (SPs) offer Virtual Private Network (VPN) services to their customers using a technique in which Customer Edge (CE) routers are routing peers of Provider Edge (PE) routers. The Border Gateway Protocol (BGP) is used to distribute the customer's routes across the provider's IP backbone network, and Multiprotocol Label Switching (MPLS) is used to tunnel customer packets across the provider's backbone. Support currently exists for both IPv4 and IPv6 VPNs; however, only Open Shortest Path First version 2 (OSPFv2) as PE-CE protocol is specified. This document extends those specifications to support OSPF version 3 (OSPFv3) as a PE-CE routing protocol. The OSPFv3 PE-CE functionality is identical to that of OSPFv2 except for the differences described in this document. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Authentication/Confidentiality for OSPFv3
            
            
            
            
              This document describes means and mechanisms to provide authentication/confidentiality to OSPFv3 using an IPv6 Authentication Header/Encapsulating Security Payload (AH/ESP) extension header. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            OSPFv2 HMAC-SHA Cryptographic Authentication
            
            
            
            
            
            
            
            
            
              This document describes how the National Institute of Standards and Technology (NIST) Secure Hash Standard family of algorithms can be used with OSPF version 2's built-in, cryptographic authentication mechanism. This updates, but does not supercede, the cryptographic authentication mechanism specified in RFC 2328. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Security Extension for OSPFv2 When Using Manual Key Management
            
            
            
            
            
            
              The current OSPFv2 cryptographic authentication mechanism as defined in RFCs 2328 and 5709 is vulnerable to both inter-session and intra- session replay attacks when using manual keying. Additionally, the existing cryptographic authentication mechanism does not cover the IP header. This omission can be exploited to carry out various types of attacks.
              This document defines changes to the authentication sequence number mechanism that will protect OSPFv2 from both inter-session and intra- session replay attacks when using manual keys for securing OSPFv2 protocol packets. Additionally, we also describe some changes in the cryptographic hash computation that will eliminate attacks resulting from OSPFv2 not protecting the IP header.
            
          
          
          
        
        
          
            Supporting Authentication Trailer for OSPFv3
            
            
            
            
            
              Currently, OSPF for IPv6 (OSPFv3) uses IPsec as the only mechanism for authenticating protocol packets. This behavior is different from authentication mechanisms present in other routing protocols (OSPFv2, Intermediate System to Intermediate System (IS-IS), RIP, and Routing Information Protocol Next Generation (RIPng)). In some environments, it has been found that IPsec is difficult to configure and maintain and thus cannot be used. This document defines an alternative mechanism to authenticate OSPFv3 protocol packets so that OSPFv3 does not depend only upon IPsec for authentication.
              The OSPFv3 Authentication Trailer was originally defined in RFC 6506. This document obsoletes RFC 6506 by providing a revised definition, including clarifications and refinements of the procedures.
            
          
          
          
        
        
          
            RIP Version 2
            
            
            
              This document specifies an extension of the Routing Information Protocol (RIP) to expand the amount of useful information carried in RIP messages and to add a measure of security. [STANDARDS-TRACK]
            
          
          
          
          
        
        
          
            RIPng for IPv6
            
            
            
            
              This document specifies a routing protocol for an IPv6 internet. It is based on protocols and algorithms currently in wide use in the IPv4 Internet [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6
            
            
            
              This memo defines the Virtual Router Redundancy Protocol (VRRP) for IPv4 and IPv6. It is version three (3) of the protocol, and it is based on VRRP (version 2) for IPv4 that is defined in RFC 3768 and in "Virtual Router Redundancy Protocol for IPv6". VRRP specifies an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN. The VRRP router controlling the IPv4 or IPv6 address(es) associated with a virtual router is called the Master, and it forwards packets sent to these IPv4 or IPv6 addresses. VRRP Master routers are configured with virtual IPv4 or IPv6 addresses, and VRRP Backup routers infer the address family of the virtual addresses being carried based on the transport protocol. Within a VRRP router, the virtual routers in each of the IPv4 and IPv6 address families are a domain unto themselves and do not overlap. The election process provides dynamic failover in the forwarding responsibility should the Master become unavailable. For IPv4, the advantage gained from using VRRP is a higher-availability default path without requiring configuration of dynamic routing or router discovery protocols on every end-host. For IPv6, the advantage gained from using VRRP for IPv6 is a quicker switchover to Backup routers than can be obtained with standard IPv6 Neighbor Discovery mechanisms. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Common YANG Data Types
            
            
            
              This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021.
            
          
          
          
        
        
          
            Common YANG Data Types for the Routing Area
            
            
            
            
            
            
            
              This document defines a collection of common data types using the YANG data modeling language. These derived common types are designed to be imported by other modules defined in the routing area.
            
          
          
          
        
        
          
            A YANG Data Model for Interface Management
            
            
            
              This document defines a YANG data model for the management of network interfaces. It is expected that interface-type-specific data models augment the generic interfaces data model defined in this document. The data model includes definitions for configuration and system state (status information and counters for the collection of statistics).
              The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in RFC 8342.
              This document obsoletes RFC 7223.
            
          
          
          
        
        
          
            Network Configuration Protocol (NETCONF)
            
            
            
            
            
            
              The Network Configuration Protocol (NETCONF) defined in this document provides mechanisms to install, manipulate, and delete the configuration of network devices. It uses an Extensible Markup Language (XML)-based data encoding for the configuration data as well as the protocol messages. The NETCONF protocol operations are realized as remote procedure calls (RPCs). This document obsoletes RFC 4741. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            RESTCONF Protocol
            
            
            
            
            
              This document describes an HTTP-based protocol that provides a programmatic interface for accessing data defined in YANG, using the datastore concepts defined in the Network Configuration Protocol (NETCONF).
            
          
          
          
        
        
          
            Using the NETCONF Protocol over Secure Shell (SSH)
            
            
            
              This document describes a method for invoking and running the Network Configuration Protocol (NETCONF) within a Secure Shell (SSH) session as an SSH subsystem. This document obsoletes RFC 4742. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            The Transport Layer Security (TLS) Protocol Version 1.3
            
            
            
              This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery.
              This document updates RFCs 5705 and 6066, and obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations.
            
          
          
          
        
        
          
            Network Configuration Access Control Model
            
            
            
            
              The standardization of network configuration interfaces for use with the Network Configuration Protocol (NETCONF) or the RESTCONF protocol requires a structured and secure operating environment that promotes human usability and multi-vendor interoperability. There is a need for standard mechanisms to restrict NETCONF or RESTCONF protocol access for particular users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. This document defines such an access control model.
              This document obsoletes RFC 6536.
            
          
          
          
          
        
        
          
            The IETF XML Registry
            
            
            
              This document describes an IANA maintained registry for IETF standards which use Extensible Markup Language (XML) related items such as Namespaces, Document Type Declarations (DTDs), Schemas, and Resource Description Framework (RDF) Schemas.
            
          
          
          
          
        
        
          
            YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)
            
            
            
              YANG is a data modeling language used to model configuration and state data manipulated by the Network Configuration Protocol (NETCONF), NETCONF remote procedure calls, and NETCONF notifications. [STANDARDS-TRACK]
            
          
          
          
        
      
      
        Informative References
        
          
            Full Network Attachment Circuit Tree Structure
            
              
            
            
          
        
        
          
            pyang
            
              
            
            
          
        
        
          
            Service Function Chaining (SFC) Architecture
            
            
            
            
              This document describes an architecture for the specification, creation, and ongoing maintenance of Service Function Chains (SFCs) in a network. It includes architectural concepts, principles, and components used in the construction of composite services through deployment of SFCs, with a focus on those to be standardized in the IETF. This document does not propose solutions, protocols, or extensions to existing protocols.
            
          
          
          
        
        
          
            A Framework for Network Slices in Networks Built from IETF Technologies
            
            
            
            
            
            
            
            
            
              This document describes network slicing in the context of networks built from IETF technologies. It defines the term "IETF Network Slice" to describe this type of network slice and establishes the general principles of network slicing in the IETF context.
              The document discusses the general framework for requesting and operating IETF Network Slices, the characteristics of an IETF Network Slice, the necessary system components and interfaces, and the mapping of abstract requests to more specific technologies. The document also discusses related considerations with monitoring and security.
              This document also provides definitions of related terms to enable consistent usage in other IETF documents that describe or use aspects of IETF Network Slices.
            
          
          
          
        
        
          
            A YANG Data Model for Augmenting VPN Service and Network Models with Attachment Circuits
            
              Orange
            
            
              Juniper
            
            
              Nokia
            
            
              Telefonica
            
            
            
                 The document specifies a module that updates existing service and
   network Virtual Private Network (VPN) modules with the required
   information to bind specific services to ACs that are created using
   the Attachment Circuit (AC) service and network models.

              
            
          
          
        
        
          
            A Framework for Automating Service and Network Management with YANG
            
            
            
            
            
            
            
              Data models provide a programmatic approach to represent services and networks. Concretely, they can be used to derive configuration information for network and service components, and state information that will be monitored and tracked. Data models can be used during the service and network management life cycle (e.g., service instantiation, service provisioning, service optimization, service monitoring, service diagnosing, and service assurance). Data models are also instrumental in the automation of network management, and they can provide closed-loop control for adaptive and deterministic service creation, delivery, and maintenance.
              This document describes a framework for service and network management automation that takes advantage of YANG modeling technologies. This framework is drawn from a network operator perspective irrespective of the origin of a data model; thus, it can accommodate YANG modules that are developed outside the IETF.
            
          
          
          
        
        
          
            YANG Tree Diagrams
            
            
            
            
              This document captures the current syntax used in YANG module tree diagrams. The purpose of this document is to provide a single location for this definition. This syntax may be updated from time to time based on the evolution of the YANG language.
            
          
          
          
          
        
        
          
            A YANG Data Model for Layer 2 Virtual Private Network (L2VPN) Service Delivery
            
            
            
            
            
            
              This document defines a YANG data model that can be used to configure a Layer 2 provider-provisioned VPN service. It is up to a management system to take this as an input and generate specific configuration models to configure the different network elements to deliver the service. How this configuration of network elements is done is out of scope for this document.
              The YANG data model defined in this document includes support for point-to-point Virtual Private Wire Services (VPWSs) and multipoint Virtual Private LAN Services (VPLSs) that use Pseudowires signaled using the Label Distribution Protocol (LDP) and the Border Gateway Protocol (BGP) as described in RFCs 4761 and 6624.
              The YANG data model defined in this document conforms to the Network Management Datastore Architecture defined in RFC 8342.
            
          
          
          
        
        
          
            YANG Data Model for L3VPN Service Delivery
            
            
            
            
            
            
              This document defines a YANG data model that can be used for communication between customers and network operators and to deliver a Layer 3 provider-provisioned VPN service. This document is limited to BGP PE-based VPNs as described in RFCs 4026, 4110, and 4364. This model is intended to be instantiated at the management system to deliver the overall service. It is not a configuration model to be used directly on network elements. This model provides an abstracted view of the Layer 3 IP VPN service configuration components. It will be up to the management system to take this model as input and use specific configuration models to configure the different network elements to deliver the service. How the configuration of network elements is done is out of scope for this document.
              This document obsoletes RFC 8049; it replaces the unimplementable module in that RFC with a new module with the same name that is not backward compatible. The changes are a series of small fixes to the YANG module and some clarifications to the text.
            
          
          
          
        
        
          
            Policy Quality of Service (QoS) Information Model
            
            
            
            
            
            
            
              This document presents an object-oriented information model for representing Quality of Service (QoS) network management policies. This document is based on the IETF Policy Core Information Model and its extensions. It defines an information model for QoS enforcement for differentiated and integrated services using policy. It is important to note that this document defines an information model, which by definition is independent of any particular data storage mechanism and access protocol.
            
          
          
          
        
        
          
            IPv6 Stateless Address Autoconfiguration
            
            
            
            
            
              This document specifies the steps a host takes in deciding how to autoconfigure its interfaces in IP version 6. The autoconfiguration process includes generating a link-local address, generating global addresses via stateless address autoconfiguration, and the Duplicate Address Detection procedure to verify the uniqueness of the addresses on a link. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Route Refresh Capability for BGP-4
            
            
            
              This document defines a new Border Gateway Protocol (BGP) capability termed 'Route Refresh Capability', which would allow the dynamic exchange of route refresh request between BGP speakers and subsequent re-advertisement of the respective Adj-RIB-Out. [STANDARDS-TRACK]
            
          
          
          
        
        
          
            Seamless Bidirectional Forwarding Detection (S-BFD)
            
            
            
            
            
            
            
              This document defines Seamless Bidirectional Forwarding Detection (S-BFD), a simplified mechanism for using BFD with a large proportion of negotiation aspects eliminated, thus providing benefits such as quick provisioning, as well as improved control and flexibility for network nodes initiating path monitoring.
              This document updates RFC 5880.
            
          
          
          
        
        
          
            Guidelines for Authors and Reviewers of Documents Containing YANG Data Models
            
              YumaWorks
            
            
              Orange
            
            
              Huawei
            
            
            
                 This memo provides guidelines for authors and reviewers of
   specifications containing YANG modules, including IANA-maintained
   modules.  Recommendations and procedures are defined, which are
   intended to increase interoperability and usability of Network
   Configuration Protocol (NETCONF) and RESTCONF protocol
   implementations that utilize YANG modules.  This document obsoletes
   RFC 8407.

   Also, this document updates RFC 8126 by providing additional
   guidelines for writing the IANA considerations for RFCs that specify
   IANA-maintained modules.

              
            
          
          
        
        
          
            A YANG Data Model for the Routing Information Protocol (RIP)
            
            
            
            
            
              This document describes a data model for the management of the Routing Information Protocol (RIP). Both RIP version 2 and RIPng are covered. The data model includes definitions for configuration, operational state, and Remote Procedure Calls (RPCs).
              The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA).
            
          
          
          
        
      
    
    


      Examples
      
        VPLS
        Let's consider the example depicted in  with two customer terminating points (CE1 and CE2). Let's also assume that the bearers to attach these CEs to the provider network are already in place. References to the identify these bearers are shown in the figure.
        
          Topology Example
          
        
        The AC service model  can be used by the provider to manage and expose the ACs over existing bearers as shown in .
        
          ACs Created Using ACaaS
          
        
        The provisioned AC at PE1 can be retrieved using the AC network model as depicted in . A similar query can be used for the AC at PE2.
        
          Example of AC Network Response (Message Body)
          
        
        Also, the AC network model can be used to retrieve the list of SAPs to which the ACs are bound as shown in .
        
          Example of AC Network Response to Retrieve the SAP (Message Body)
          
        
      
      
        Parent AC
        In reference to the topology depicted in , PE2 has a SAP which terminates an AC with two peer SAPs (CE2 and CE5). In order to control data that is specific to each of these peer SAPs over the same AC, child ACs can be instantiated as depicted in .
        
          Example of Child ACs
          
        
         shows how to bind the parent AC to a SAP.
        
          Example of Binding Parent AC to SAPs
          
        
      
    
    
      Acknowledgments
      This document builds on  and .
      Thanks to Moti Morgenstern for the review and comments.
      Thanks to Martin Björklund for the yangdoctors review and Gyan Mishra for the rtg-dir review.
    
    
      Contributors
      
        Nokia
        
          victor.lopez@nokia.com
        
      
      
        Ribbon Communications
        
          Ivan.Bykov@rbbn.com
        
      
      
        Huawei
        
          bill.wu@huawei.com
        
      
      
        KDDI
        
          ke-oogaki@kddi.com
        
      
      
        Vodafone
        
          luis-angel.munoz@vodafone.com