]> 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 OPSAWG Slice Service L3VPN L2VPN Automation Network Automation Orchestration service delivery Service provisioning service segmentation service flexibility service simplification Network Service 3GPP Network Slicing 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. 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 (e.g., Service Functions (SFs), Customer Premises Equipment (CPEs), Autonomous System Border Routers (ASBRs), data centers gateways, or Internet Exchange Points). A connectivity service is basically about ensuring data transfer received from (or destined to) a given terminating point to (or from) other terminating points that belong to the same customer/service, an interconnection node, or an ancillary node. A set of objectives for the connectivity service may eventually be negotiated and agreed upon between a customer a network provider. For that data transfer to take place within the provider network, it is assumed that adequate setup is provisioned over the links that connect customer terminating points and a provider network (a Provider Edge (PE), typically) so that data can be successfully exchanged over these links. The required setup is referred to in this document as Attachment Circuits (ACs), while the underlying link is referred to as "bearer". This document adheres to the definition of an attachment circuit as provided in , especially:

• Routers can be attached to each other, or to end systems, in a variety of different ways: PPP connections, ATM Virtual Circuits (VCs), Frame Relay VCs, ethernet interfaces, Virtual Local Area Networks (VLANs) on ethernet interfaces, GRE tunnels, Layer 2 Tunneling Protocol (L2TP) tunnels, IPsec tunnels, etc. We will use the term "attachment circuit" to refer generally to some such means of attaching to a router. An attachment circuit may be the sort of connection that is usually thought of as a "data link", or it may be a tunnel of some sort; what matters is that it be possible for two devices to be network layer peers over the attachment circuit.

When a customer requests a new value-added service, the service can be bound to existing attachment circuits or trigger the instantiation of new attachment circuits. Whether these attachment circuits are specific to a given service or be shared to deliver a variety of services is deployment-specific. An example of attachment circuits is depicted in . A Customer Edge (CE) may be a physical node or a logical entity. A CE is seen by the network as a peer Service Attachment Point (SAP) . CEs may be dedicated to one single service (e.g., Layer 3 Virtual Private Network (VPN) or Layer 2 VPN) or host multiple services (e.g., Service Functions ). A single AC (as seen by a network provider) may be bound to one or multiple peer SAPs (e.g., "CE1" and "CE2"). For example, and as discussed in , multiple CEs can be attached to a PE over the same attachment circuit. This is typically implemented if the Layer 2 infrastructure between the CE and the network provides a multipoint service. The same CE may terminate multiple ACs. These ACs may be over the same or distinct bearers.

Examples of ACs

This document specifies a common module ("ietf-ac-common") for attachment circuits (). The model is designed with the intent to be reusable by other models and, therefore, ensure consistent AC structures among modules that manipulate ACs. For example, the common model can be reused by service models to expose AC-as-a-Service (ACaaS) (e.g., ), service models that require binding a service to a set of ACs (e.g., Network Slice Service )), network models to provision ACs (e.g., ), device models, etc. The common AC module eases data inheritance between modules (e.g., from service to network models as per ). The YANG data model in this document conforms to the Network Management Datastore Architecture (NMDA) defined in .

Editorial Note (To be removed by RFC Editor) Note to the RFC Editor: This section is to be removed prior to publication. This document contains placeholder values that need to be replaced with finalized values at the time of publication. This note summarizes all of the substitutions that are needed. Please apply the following replacements:

• XXXX --> the assigned RFC number for this I-D
• 2023-11-13 --> the actual date of the publication of this document

Conventions and Definitions 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 Layer 2 Network Model (L2NM) and the Layer 3 Network Model (L3NM) . This document uses the following term:

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).

The names of data nodes are prefixed using the prefix associated with the corresponding imported YANG module as shown in : Modules and Their Associated Prefixes

Prefix	Module	Reference
inet	ietf-inet-types
key-chain	ietf-key-chain
nacm	ietf-netconf-acm
vpn-common	ietf-vpn-common
yang	ietf-yang-types

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".

Description of the AC Common YANG Module The full tree diagram of the module can be generated using the "pyang" tool with "-f tree --tree-print-groupings" command-line parameters. That tree is not included here because it is too long (). Instead, subtrees are provided for the reader's convenience.

• The full tree of the "ietf-ac-common" module is available at .

Features The module defines the following features:

'layer2-ac':

Used to indicate support of ACs with Layer 2 properties.

'layer3-ac':

Used to indicate support of ACs with Layer 3 properties.

'server-assigned-reference':

Used to indicate support of server-generated references to access relevant resources.

For example, a bearer request is first created using a name which is assigned by the client, but if this feature is supported, the request will also include a server-generated reference. That reference can be used when requesting the creating of an AC over the existing bearer.

Identities The module defines a set of identities, including the following:

'address-allocation-type':

Used to specify the IP address allocation type in an AC. For example, this identity can used to indicate whether the provider network provides DHCP service, DHCP relay, or static addressing. Note that for the IPv6 case, Stateless Address Autoconfiguration (SLAAC) can be used.

'local-defined-next-hop':

Used to specify next hop actions. For example, this identity can be used to indicate an action to discard traffic for a given destination or treat traffic towards addresses within the specified next-hop prefix as though they are connected to a local link.

'l2-tunnel-type':

Uses to control the Layer 2 tunnel selection for an AC. The current version supports indicating pseudowire, Virtual Private LAN Service (VPLS), and Virtual eXtensible Local Area Network (VXLAN).

'precedence-type':

Used to indicate the redundancy type when requesting ACs. For example, this identity can be used to tag primary and secondary ACs.

'bgp-capability':

Used to indicate a BGP capability . Examples of BGP capabilities are Multiprotocol extensions for BGP-4 , route refresh , graceful restart , ADD-PATH , or BGP Role }.

'role':

Used to indicate the type of an AC: User-to-Network Interface (UNI), Network-to-Network Interface (NNI), or public NNI.

New administrative status types:

In addition to the status types already defined in , this document defines:

• 'awaiting-validation' to report that a request is pending an adiministrator approval.
• 'awaiting-processing' to report that a request was approved and validated, but is awaiting more processing before activation.
• 'admin-prohibited' to report that a request cannot be handled because of administrative policies.
• 'rejected' to report that a request was rejected reasons not covered by the other status types.

Reusable Groupings The module also defines a set of reusable groupings, including the following:

'op-instructions' ():

Defines a set of parameters to specify scheduling instructions and report related events for a service request (e.g., AC or bearer).

Operational Instructions Grouping

Layer 2 encapsulations ():

Groupings for the following encapsulation schemes are supported: dot1Q, QinQ, and priority-tagged.

Layer 2 tunnel services ():

These groupings are used to define Layer 2 tunnel services that may be needed for the activation of an AC. Examples of supported Layer 2 services are the pseudowire (), VPLS, or VXLAN .

Layer 2 Connection Groupings

Layer 3 address allocation ():

Defines both IPv4 and IPv6 groupings to specify IP address allocation over an AC. Both dynamic and static address schemes are supported.

IP connections ()::

Defines IPv4 and IPv6 groupings for managing Layer 3 connectivity over an AC. Both basic and more elaborated IP connection groupings are supported.

Layer 3 Connection Groupings

Routing parameters & OAM ():

In addition to static routing, the module supports the following routing protocols: BGP , OSPF or , IS-IS , and RIP . For all supported routing protocols, 'address-family' indicates whether IPv4, IPv6, or both address families are to be activated. For example, this parameter is used to determine whether RIPv2 , RIP Next Generation (RIPng), or both are to be enabled . More details about supported routing groupings are provided hereafter:

• Authentication: These groupings include the required information to manage the authentication of OSPF, IS-IS, BGP, and RIP. Similar to , this version of the common AC 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 (Section 3.1 of ).
• BGP peer groups: Includes a set of parameters to identify a BGP peer group. Such a group can be defined by providing a local AS Number (ASN), a customer's ASN, and the address families to be activated for this group. BGP peer groups can be identified by a name.
• Basic parameters: These groupings include the minimal set of routing configuration that is required for the activation of OSPF, IS-IS, BGP, and RIP.
• Static routing: Parameters to configure an entry of a list of IP static routing entries.

The 'redundancy-group' grouping lists the groups to which an AC belongs . For example, the 'group-id' is used to associate redundancy or protection constraints of ACs.

Layer 3 Connection Groupings

Bandwidth parameters ():

Bandwidth parameters can be represented using the Committed Information Rate (CIR), the Excess Information Rate (EIR), or the Peak Information Rate (PIR).

These parameters can be provided per bandwidth type. Type values are taken from , e.g.,:

• 'bw-per-cos':

  The bandwidth is per Class of Service (CoS).

• 'bw-per-site':

  The bandwidth is to all ACs that belong to the same site.

Bandwidth Groupings

Common Attachment Circuit YANG Module This module uses types defined in , , and . 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 common attachment circuit (AC) YANG model. 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 Common YANG Data Model for Attachment Circuits"; } /****************************Features************************/ feature layer2-ac { description "Indicates support of Layer 2 ACs."; } feature layer3-ac { description "Indicates support of Layer 3 ACs."; } feature server-assigned-reference { description "This feature indicates support for server-generated references and use of such references to access related resources."; } /****************************Identities************************/ // IP address allocation types identity address-allocation-type { description "Base identity for address allocation type in the AC."; } identity provider-dhcp { base address-allocation-type; description "The provider's network provides a DHCP service to the customer."; } identity provider-dhcp-relay { base address-allocation-type; description "The provider's network provides a DHCP relay service to the customer."; } identity provider-dhcp-slaac { if-feature "vpn-common:ipv6"; base address-allocation-type; description "The provider's network provides a DHCP service to the customer as well as IPv6 Stateless Address Autoconfiguration (SLAAC)."; reference "RFC 4862: IPv6 Stateless Address Autoconfiguration"; } identity static-address { base address-allocation-type; description "The provider's network provides static IP addressing to the customer."; } identity slaac { if-feature "vpn-common:ipv6"; base address-allocation-type; description "The provider's network uses IPv6 SLAAC to provide addressing to the customer."; reference "RFC 4862: IPv6 Stateless Address Autoconfiguration"; } identity dynamic-infra { base address-allocation-type; description "The IP address is dynamically allocated by the hosting infrastrcture."; } // next-hop actions identity local-defined-next-hop { description "Base identity of local defined next hops."; } identity discard { base local-defined-next-hop; description "Indicates an action to discard traffic for the corresponding destination. For example, this can be used to black-hole traffic."; } identity local-link { base local-defined-next-hop; description "Treat traffic towards addresses within the specified next-hop prefix as though they are connected to a local link."; } // Layer 2 tunnel types identity l2-tunnel-type { description "Base identity for Layer 2 tunnel selection for an AC."; } identity pseudowire { base l2-tunnel-type; description "Pseudowire tunnel termination for the AC."; } identity vpls { base l2-tunnel-type; description "Virtual Private LAN Service (VPLS) tunnel termination for the AC."; } identity vxlan { base l2-tunnel-type; description "Virtual eXtensible Local Area Network (VXLAN) tunnel termination for the AC."; } // Tagging precedence identity precedence-type { description "Redundancy type. The service can be created with primary and secondary tagging."; } identity primary { base precedence-type; description "Identifies the main attachment circuit."; } identity secondary { base precedence-type; description "Identifies the secondary attachment circuit."; } /* BGP Capability Identities. */ identity bgp-capability { description "Base identity for a BGP capability."; reference "RFC 5492: Capabilities Advertisement with BGP-4"; } identity mp-bgp { base bgp-capability; description "Multi-protocol extensions to BGP."; reference "RFC 4760: Multiprotocol Extentions for BGP-4"; } identity route-refresh { base bgp-capability; description "Route refresh capability."; reference "RFC 2918: Route Refresh Capability for BGP-4."; } identity graceful-restart { base bgp-capability; description "Graceful restart capability."; reference "RFC 4724: Graceful Restart Mechanism for BGP"; } identity add-paths { base bgp-capability; description "A capability that allows the advertisement of multiple paths for the same address prefix without the new paths implicitly replacing any previous ones."; reference "RFC 7911: Advertisement of Multiple Paths in BGP"; } identity ebgp-role { base bgp-capability; description "A capability that allows the advertisement of the BGP role when establising a session."; reference "RFC 9234: Route Leak Prevention and Detection Using Roles in UPDATE and OPEN Messages, Section 4.1"; } // AC Type identity role { description "Base identity for the network role of an AC."; } identity uni { base role; description "User-to-Network Interface (UNI)."; } identity nni { base role; description "Network-to-Network Interface (NNI)."; } identity public-nni { base role; description "Public peering."; } // More Admin status types identity awaiting-validation { base vpn-common:administrative-status; description "This administrative status reflects that a request is pending an adiministrator approval."; } identity awaiting-processing { base vpn-common:administrative-status; description "This administrative status reflects that a request was approved and validated, but is awaiting more processing before activation."; } identity admin-prohibited { base vpn-common:administrative-status; description "This administrative status reflects that a request cannot be handled because of administrative policies."; } identity rejected { base vpn-common:administrative-status; description "This administrative status reflects that a request was rejected because, e.g., there are no sufficient resources or other reasons not covered by the other status types."; } identity bgp-role { description "Used to indicate BGP role when establishing a BGP session."; reference "RFC 9234: Route Leak Prevention and Detection Using Roles in UPDATE and OPEN Messages, Section 4"; } identity provider { base bgp-role; description "The local AS is a transit provider of the remote AS."; } identity client { base bgp-role; description "The local AS is a transit provider of the remote AS."; } identity rs { base bgp-role; description "The local AS is a Route Server (RS)."; } identity rs-client { base bgp-role; description "The local AS is a client of an RS and the RS is the remote AS."; } identity peer { base bgp-role; description "The local and remote ASes have a peering relationship."; } /****************************Typedefs************************/ typedef predefined-next-hop { type identityref { base local-defined-next-hop; } description "Predefined next-hop designation for locally generated routes."; } typedef area-address { type string { pattern '[0-9A-Fa-f]{2}(\.[0-9A-Fa-f]{4}){0,6}'; } description "This type defines the area address format."; } /************************Reusable groupings********************/ /**** Service Status ****/ grouping service-status { description "Service status grouping."; container status { description "Service status."; container admin-status { description "Administrative service status."; leaf status { type identityref { base vpn-common:administrative-status; } description "Administrative service status."; } leaf last-change { type yang:date-and-time; config false; description "Indicates the actual date and time of the service status change."; } } container oper-status { config false; description "Operational service status."; uses vpn-common:oper-status-timestamp; } } } /**** A set of profiles ****/ grouping ac-profile-cfg { description "Grouping for AC profile configuration."; container valid-provider-identifiers { description "Container for valid provider profile identifiers. The profiles only have significance within the service provider's administrative domain."; list encryption-profile-identifier { key "id"; description "List of encryption profile identifiers."; leaf id { type string; description "Identification of the encryption profile to be used."; } } list qos-profile-identifier { key "id"; description "List of QoS profile identifiers."; leaf id { type string; description "Identification of the QoS profile to be used."; } } list failure-detection-profile-identifier { key "id"; description "List of BFD profile identifiers."; leaf id { type string; description "Identification of the a failure detection (e.g., BFD) profile to be used."; } } list forwarding-profile-identifier { key "id"; description "List of forwarding profile identifiers."; leaf id { type string; description "Identification of the forwarding profile to be used."; } } list routing-profile-identifier { key "id"; description "List of routing profile identifiers."; leaf id { type string; description "Identification of the routing profile to be used by the routing protocols over an AC."; } } nacm:default-deny-write; } } /**** Operational instructions ****/ grouping op-instructions { description "Scheduling instructions."; leaf requested-start { type yang:date-and-time; description "Indicates the requested date and time when the service is expected to be active."; } leaf requested-stop { type yang:date-and-time; description "Indicates the requested date and time when the service is expected to be disabled."; } leaf actual-start { type yang:date-and-time; config false; description "Indicates the actual date and time when the service actually was enabled."; } leaf actual-stop { type yang:date-and-time; config false; description "Indicates the actual date and time when the service actually was disabled."; } } /**** Layer 2 encapsulations ****/ // Dot1q grouping dot1q { description "Defines a grouping for tagged interfaces."; leaf tag-type { type identityref { base vpn-common:tag-type; } description "Tag type."; } leaf cvlan-id { type uint16 { range "1..4094"; } description "VLAN identifier."; } } // priority-tagged grouping priority-tagged { description "Priority tagged."; leaf tag-type { type identityref { base vpn-common:tag-type; } description "Tag type."; } } // QinQ grouping qinq { description "Includes QinQ parameters."; leaf tag-type { type identityref { base vpn-common:tag-type; } description "Tag type."; } leaf svlan-id { type uint16 { range "1..4094"; } description "Service VLAN (S-VLAN) identifier."; } leaf cvlan-id { type uint16 { range "1..4094"; } description "Customer VLAN (C-VLAN) identifier."; } } /**** Layer 2 tunnel services ****/ // pseudowire (PW) grouping pseudowire { description "Includes pseudowire termination parameters."; leaf vcid { type uint32; description "Indicates a PW or virtual circuit (VC) identifier."; } leaf far-end { type union { type uint32; type inet:ip-address; } description "Neighbor reference."; reference "RFC 8077: Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP), Section 6.1"; } } // VPLS grouping vpls { description "VPLS termination parameters."; leaf vcid { type uint32; description "VC identifier."; } leaf-list far-end { type union { type uint32; type inet:ip-address; } description "Neighbor reference."; } } // VXLAN grouping vxlan { description "VXLAN termination parameters."; leaf vni-id { type uint32; description "VXLAN Network Identifier (VNI)."; } leaf peer-mode { type identityref { base vpn-common:vxlan-peer-mode; } description "Specifies the VXLAN access mode. By default, the peer mode is set to 'static-mode'."; } leaf-list peer-ip-address { type inet:ip-address; description "List of a peer's IP addresses."; } } // Layer 2 Tunnel service grouping l2-tunnel-service { description "Defines a Layer 2 tunnel termination."; leaf type { type identityref { base l2-tunnel-type; } description "Selects the tunnel termination type for an AC."; } container pseudowire { when "derived-from-or-self(../type, 'ac-common:pseudowire')" { description "Only applies when the Layer 2 service type is 'pseudowire'."; } description "Includes pseudowire termination parameters."; uses pseudowire; } container vpls { when "derived-from-or-self(../type, 'ac-common:vpls')" { description "Only applies when the Layer 2 service type is 'vpls'."; } description "VPLS termination parameters."; uses vpls; } container vxlan { when "derived-from-or-self(../type, 'ac-common:vxlan')" { description "Only applies when the Layer 2 service type is 'vxlan'."; } description "VXLAN termination parameters."; uses vxlan; } } /**** Layer 3 connection *****/ // IPv4 allocation type grouping ipv4-allocation-type { description "IPv4-specific parameters."; leaf prefix-length { type uint8 { range "0..32"; } description "Subnet prefix length expressed in bits. It is applied to both local and customer addresses."; } leaf address-allocation-type { type identityref { base address-allocation-type; } must "not(derived-from-or-self(current(), 'ac-common:slaac') " + "or derived-from-or-self(current(), " + "'ac-common:provider-dhcp-slaac'))" { error-message "SLAAC is only applicable to IPv6."; } description "Defines how IPv4 addresses are allocated to the peer site."; } } // IPv6 allocation type grouping ipv6-allocation-type { description "IPv6-specific parameters."; leaf prefix-length { type uint8 { range "0..128"; } description "Subnet prefix length expressed in bits. It is applied to both local and customer addresses."; } leaf address-allocation-type { type identityref { base address-allocation-type; } description "Defines how IPv6 addresses are allocated to the peer site."; } } // Basic parameters for IPv4 connection grouping ipv4-connection-basic { description "Basic set fof IPv4-specific parameters for the connection."; uses 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 provider-dhcp { description "Parameters related to DHCP-allocated addresses. IP addresses are allocated by DHCP, that 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 an AC."; } } 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."; } } } } } } // Basic parameters for IPv6 connection grouping ipv6-connection-basic { description "Basic set fof IPv6-specific parameters for the connection."; uses 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 provider-dhcp { description "Parameters related to DHCP-allocated addresses. IP addresses are allocated by DHCP, that 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 the AC."; } } 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."; } } } } } } // Full parameters for the IPv4 connection grouping ipv4-connection { description "IPv4-specific parameters."; leaf local-address { type inet:ipv4-address; description "The IP address used at the provider's interface."; } leaf virtual-address { type inet:ipv4-address; description "This addresss may be used for redundancy purposes."; } uses 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 the AC."; } } 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 AC."; } } 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."; } } } } } // Full parameters for the IPv6 connection grouping ipv6-connection { description "IPv6-specific parameters."; leaf local-address { type inet:ipv6-address; description "IPv6 address of the provider side."; } leaf virtual-address { type inet:ipv6-address; description "This addresss may be used for redundancy purposes."; } uses 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 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 IPv6 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 IP address of the connection."; leaf address-id { type string; description "An identifier of the static IPv6 address."; } leaf customer-address { type inet:ipv6-address; description "An IPv6 address of the customer side."; } } } } } /**** Routing ****/ // Routing authentication grouping bgp-authentication { description "Grouping for BGP authentication parameters."; container authentication { description "Container for BGP authentication parameters."; leaf enabled { type boolean; description "Enables or disables authentication."; } container keying-material { when "../enabled = 'true'"; description "Container for describing how a BGP routing session is to be secured on an AC."; choice option { description "Choice of authentication options."; case ao { description "Uses the TCP Authentication Option (TCP-AO)."; reference "RFC 5925: The TCP Authentication Option"; leaf enable-ao { type boolean; description "Enables the TCP-AO."; } leaf ao-keychain { type key-chain:key-chain-ref; description "Reference to the TCP-AO key chain."; reference "RFC 8177: YANG Data Model for Key Chains"; } } case md5 { description "Uses MD5 to secure the session."; reference "RFC 4364: BGP/MPLS IP Virtual Private Networks (VPNs), Section 13.2"; leaf md5-keychain { type key-chain:key-chain-ref; description "Reference to the MD5 key chain."; reference "RFC 8177: YANG Data Model for Key Chains"; } } case explicit { leaf key-id { type uint32; description "Key identifier."; } leaf key { type string; description "BGP authentication key. This model only supports the subset of keys that are representable as ASCII strings."; } leaf crypto-algorithm { type identityref { base key-chain:crypto-algorithm; } description "Indicates the cryptographic algorithm associated with the key."; } } } } } } grouping ospf-authentication { description "Authentication configuration."; container authentication { description "Container for OSPF authentication parameters."; leaf enabled { type boolean; description "Enables or disables authentication."; } container keying-material { when "../enabled = 'true'"; description "Container for describing how an OSPF session is to be secured for this AC."; choice option { description "Options for OSPF authentication."; case auth-key-chain { leaf key-chain { type key-chain:key-chain-ref; description "Name of the key chain."; } } case auth-key-explicit { leaf key-id { type uint32; description "Key identifier."; } leaf key { type string; description "OSPF authentication key. This model only supports the subset of keys that are representable as ASCII strings."; } leaf crypto-algorithm { type identityref { base key-chain:crypto-algorithm; } description "Indicates the cryptographic algorithm associated with the key."; } } } } } } grouping isis-authentication { description "IS-IS authentication configuration."; container authentication { description "Container for IS-IS authentication parameters."; leaf enabled { type boolean; description "Enables or disables authentication."; } container keying-material { when "../enabled = 'true'"; description "Container for describing how an IS-IS session is secured over an AC."; choice option { description "Options for IS-IS authentication."; case auth-key-chain { leaf key-chain { type key-chain:key-chain-ref; description "Name of the key chain."; } } case auth-key-explicit { leaf key-id { type uint32; description "Key identifier."; } leaf key { type string; description "IS-IS authentication key. This model only supports the subset of keys that are representable as ASCII strings."; } leaf crypto-algorithm { type identityref { base key-chain:crypto-algorithm; } description "Indicates the cryptographic algorithm associated with the key."; } } } } } } grouping rip-authentication { description "RIP authentication configuration."; container authentication { description "Container for RIP authentication parameters."; leaf enabled { type boolean; description "Enables or disables authentication."; } container keying-material { when "../enabled = 'true'"; description "Container for describing how a RIP session is to be secured on this AC."; choice option { description "Specifies the authentication scheme."; case auth-key-chain { leaf key-chain { type key-chain:key-chain-ref; description "Name of the key chain."; } } case auth-key-explicit { leaf key { type string; description "RIP authentication key. This model only supports the subset of keys that are representable as ASCII strings."; } leaf crypto-algorithm { type identityref { base key-chain:crypto-algorithm; } description "Indicates the cryptographic algorithm associated with the key."; } } } } } } // Basic routing parameters grouping bgp-peer-group-without-name { description "Identifies a BGP peer-group configured on the local system."; leaf local-as { type inet:as-number; description "Indicates a local AS Number (ASN). This ASN is exposed to a customer so that it knows which ASN to use to set up a BGP session."; } leaf peer-as { type inet:as-number; 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 role { type identityref { base ac-common:bgp-role; } description "Specifies the BGP role (provider, customer, peer, etc.)."; reference "RFC 9234: Route Leak Prevention and Detection Using Roles in UPDATE and OPEN Messages, Section 4"; } } grouping bgp-peer-group-with-name { description "Identifies a BGP peer-group configured on the local system - identified by a peer-group name."; leaf name { type string; description "Name of the BGP peer-group."; } uses bgp-peer-group-without-name; } grouping ospf-basic { description "Configuration specific to OSPF."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both are to be activated."; } leaf area-id { type yang:dotted-quad; mandatory true; description "Area ID."; reference "RFC 4577: OSPF as the Provider/Customer Edge Protocol for BGP/MPLS IP Virtual Private Networks (VPNs), Section 4.2.3 RFC 6565: OSPFv3 as a Provider Edge to Customer Edge (PE-CE) Routing Protocol, Section 4.2"; } leaf metric { type uint16; description "Metric of the AC. It is used in the routing state calculation and path selection."; } } grouping isis-basic { description "Basic configuration specific to IS-IS."; leaf address-family { type identityref { base vpn-common:address-family; } description "Indicates whether IPv4, IPv6, or both are to be activated."; } leaf area-address { type area-address; mandatory true; description "Area address."; } } // Static routing grouping ipv4-static-rtg-entry { description "Paramters to configure a specific IPv4 static routing entry."; leaf lan { type inet:ipv4-prefix; description "LAN prefix."; } leaf lan-tag { type string; description "Internal tag to be used in service policies."; } leaf next-hop { type union { type inet:ip-address; type predefined-next-hop; } description "The next hop that is to be used for the static route. This may be specified as an IP address or a predefined next-hop type (e.g., 'discard' or 'local-link')."; } leaf metric { type uint32; description "Indicates the metric associated with the static route."; } } grouping ipv4-static-rtg { description "Configuration specific to IPv4 static routing."; list ipv4-lan-prefixes { if-feature "vpn-common:ipv4"; key "lan next-hop"; description "List of LAN prefixes for the site."; uses ipv4-static-rtg-entry; uses ac-common:service-status; } } grouping ipv6-static-rtg-entry { description "Paramters to configure a specific IPv6 static routing entry."; leaf lan { type inet:ipv6-prefix; description "LAN prefixes."; } leaf lan-tag { type string; description "Internal tag to be used in service (e.g., VPN) policies."; } leaf next-hop { type union { type inet:ip-address; type predefined-next-hop; } description "The next hop that is to be used for the static route. This may be specified as an IP address or a predefined next-hop type (e.g., 'discard' or 'local-link')."; } leaf metric { type uint32; description "Indicates the metric associated with the static route."; } } grouping ipv6-static-rtg { description "Configuration specific to IPv6 static routing."; list ipv6-lan-prefixes { if-feature "vpn-common:ipv6"; key "lan next-hop"; description "List of LAN prefixes for the site."; uses ipv6-static-rtg-entry; uses ac-common:service-status; } } // OAM grouping bfd { description "A grouping for basic BFD."; 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. If the provider doesn't allow the customer to use this function, fixed values will not be set."; reference "RFC 5880: Bidirectional Forwarding Detection (BFD), Section 6.8.18"; } } // redundancy grouping redundancy-group { description "A grouping for redundancy group."; 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."; } } } // QoS grouping bandwidth-parameters { description "A grouping for bandwidth parameters."; leaf cir { type uint64; units "bps"; description "Committed Information Rate (CIR). The maximum number of bits that a port can receive or send during one second over an interface."; } leaf cbs { type uint64; units "bytes"; description "Committed Burst Size (CBS). CBS controls the bursty nature of the traffic. Traffic that does not use the configured CIR accumulates credits until the credits reach the configured CBS."; } leaf eir { type uint64; units "bps"; description "Excess Information Rate (EIR), i.e., excess frame delivery allowed not subject to a Service Level Agreement (SLA). The traffic rate can be limited by EIR."; } leaf ebs { type uint64; units "bytes"; description "Excess Burst Size (EBS). The bandwidth available for burst traffic from the EBS is subject to the amount of bandwidth that is accumulated during periods when traffic allocated by the EIR policy is not used."; } leaf pir { type uint64; units "bps"; description "Peak Information Rate (PIR), i.e., maximum frame delivery allowed. It is equal to or less than sum of CIR and EIR."; } leaf pbs { type uint64; units "bytes"; description "Peak Burst Size (PBS)."; } } grouping bandwidth-per-type { description "Grouping for bandwidth per type."; list bandwidth { key "bw-type"; description "List for bandwidth per type data nodes."; leaf bw-type { type identityref { base vpn-common:bw-type; } description "Indicates the bandwidth type."; } choice type { description "Choice based upon bandwidth type."; case per-cos { description "Bandwidth per CoS."; list cos { key "cos-id"; description "List of Class of Services."; leaf cos-id { type uint8; description "Identifier of the CoS, indicated by a Differentiated Services Code Point (DSCP) or a CE-CLAN CoS (802.1p) value in the service frame."; reference "IEEE Std 802.1Q: Bridges and Bridged Networks"; } uses bandwidth-parameters; } } case other { description "Other bandwidth types."; uses bandwidth-parameters; } } } } } ]]>

Security Considerations This section uses the template described in . The YANG module specified in this document defines 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. The "ietf-ac-common" module defines a set of identities, types, and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. YANG modules that use the groupings that are defined in this document should identify the corresponding security considerations. For example, reusing some of these groupings will expose privacy-related information (e.g., 'ipv6-lan-prefixes' or 'ipv4-lan-prefixes'). Disclosing such information may be considered a violation of the customer-provider trust relationship. Several groupings ('bgp-authentication', 'ospf-authentication', 'isis-authentication', and 'rip-authentication') rely upon for authentication purposes. As such, modules that will reuse these groupings will inherit the security considerations discussed in Section 5 of . Also, these groupings 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 common AC 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 ISO 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. This document introduces a collection of common data types to be used with the YANG data modeling language. This document obsoletes RFC 6021. 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. 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. 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. This document defines an Optional Parameter, called Capabilities, that is expected to facilitate the introduction of new capabilities in the Border Gateway Protocol (BGP) by providing graceful capability advertisement without requiring that BGP peering be terminated. This document obsoletes RFC 3392. [STANDARDS-TRACK] 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. This document describes Virtual eXtensible Local Area Network (VXLAN), which is used to address the need for overlay networks within virtualized data centers accommodating multiple tenants. The scheme and the related protocols can be used in networks for cloud service providers and enterprise data centers. This memo documents the deployed VXLAN protocol for the benefit of the Internet community. 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] 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] 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] This memo specifies an integrated routing protocol, based on the OSI Intra-Domain IS-IS Routing Protocol, which may be used as an interior gateway protocol (IGP) to support TCP/IP as well as OSI. This allows a single routing protocol to be used to support pure IP environments, pure OSI environments, and dual environments. This specification was developed by the IS-IS working group of the Internet Engineering Task Force. [STANDARDS-TRACK] This document specifies a method for exchanging IPv6 routing information using the IS-IS routing protocol. The described method utilizes two new TLVs: a reachability TLV and an interface address TLV to distribute the necessary IPv6 information throughout a routing domain. Using this method, one can route IPv6 along with IPv4 and OSI using a single intra-domain routing protocol. [STANDARDS-TRACK] 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] 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] 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] 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] 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). 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] 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. 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 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 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] 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. 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. 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. Huawei Technologies Huawei Technologies Ciena Cisco Systems, Inc Cisco Systems, Inc This document defines a YANG data model for RFC 9543 Network Slice Service. The model can be used in the Network Slice Service interface between a customer and a provider that offers RFC 9543 Network Slice Services. Orange Juniper Telefonica Nokia Huawei Technologies 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 the YANG Data Models for Bearers and 'Attachment Circuits'-as-a-Service (ACaaS) (I-D.ietf- opsawg-teas-attachment-circuit). The module augments the base network ('ietf-network') and the Service Attachment Point (SAP) models with the detailed information for the provisioning of attachment circuits in Provider Edges (PEs). 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. 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. 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. 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. 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. 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. Orange Juniper Nokia Telefonica The document specifies a module that updates existing service (i.e., the Layer 2 Service Model (L2SM) and the Layer 3 Service Model (L3SM)) and network (i.e., the Layer 2 Network Model (L2NM) and the Layer 3 Network Model (L3NM)) Virtual Private Network (VPN) modules with the required information to bind specific VPN services to Attachment Circuits (ACs) that are created using the AC service ("ietf-ac-svc") and network ("ietf-ac-ntw") models. 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] This document defines extensions to BGP-4 to enable it to carry routing information for multiple Network Layer protocols (e.g., IPv6, IPX, L3VPN, etc.). The extensions are backward compatible - a router that supports the extensions can interoperate with a router that doesn't support the extensions. [STANDARDS-TRACK] 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] This document describes a mechanism for BGP that would help minimize the negative effects on routing caused by BGP restart. An End-of-RIB marker is specified and can be used to convey routing convergence information. A new BGP capability, termed "Graceful Restart Capability", is defined that would allow a BGP speaker to express its ability to preserve forwarding state during BGP restart. Finally, procedures are outlined for temporarily retaining routing information across a TCP session termination/re-establishment. The mechanisms described in this document are applicable to all routers, both those with the ability to preserve forwarding state during BGP restart and those without (although the latter need to implement only a subset of the mechanisms described in this document). [STANDARDS-TRACK] This document defines a BGP extension that allows the advertisement of multiple paths for the same address prefix without the new paths implicitly replacing any previous ones. The essence of the extension is that each path is identified by a Path Identifier in addition to the address prefix. Route leaks are the propagation of BGP prefixes that violate assumptions of BGP topology relationships, e.g., announcing a route learned from one transit provider to another transit provider or a lateral (i.e., non-transit) peer or announcing a route learned from one lateral peer to another lateral peer or a transit provider. These are usually the result of misconfigured or absent BGP route filtering or lack of coordination between autonomous systems (ASes). Existing approaches to leak prevention rely on marking routes by operator configuration, with no check that the configuration corresponds to that of the External BGP (eBGP) neighbor, or enforcement of the two eBGP speakers agreeing on the peering relationship. This document enhances the BGP OPEN message to establish an agreement of the peering relationship on each eBGP session between autonomous systems in order to enforce appropriate configuration on both sides. Propagated routes are then marked according to the agreed relationship, allowing both prevention and detection of route leaks. 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. The document also updates RFC 6020 by clarifying how modules and their revisions are handled by IANA. 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).

Acknowledgments The document reuses many of the structures that were defined in and . Thanks to Ebben Aries for the YANG Doctors review, Andy Smith and Gyanh Mishra for the rtg-dir reviews. Thanks to Reza Rokui for the Shepherd 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