BGP node-ID EC extension

Introduction Each node in a network can be represented by an IP address with global reachability—an IPv4 address for IPv4 networks or an IPv6 address for IPv6 networks. However, in certain networks such as AI Fabric, using IP addresses to identify nodes may not be the most efficient approach; since the scale typically does not exceed 64k nodes, a 2-byte node-ID serves as a more efficient form of identification. This means that within an network like AI Fabric, a unique node ID can be assigned to identify each forwarding node—such as the Leaf or Spine switches in a Clos or Fat-Tree topology. This identifier can be associated with the actual IP address, allowing the node ID to be used to represent the node during forwarding or fault response processes. This document defines a new extended community attribute to advertise the node-ID.

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in .

Format A new Sub-Type for identifying the node-ID will be defined within the Transitive Opaque Extended Community ( and ), with the following format:

Sub-Type: TBD. This indicates that this is the node-ID extended community;
node-ID: 2 octets, the unique value used to identify a node.
Reserved: 4 octets, MUST be set to 0, and this part MUST be ignored upon receipt.

Specification Nodes in the network can be assigned a unique node-ID—either through manual configuration or via allocation from a controller. When advertising the route for its loopback address, each node includes the node-ID in the extended community attribute. This value cannot be modified by any node other than the source node that generated it. Once all devices have advertised this information, every node becomes aware of the mappings between nodes and their respective node-IDs within the network. Not every node in the network requires a node-ID; nodes that perform only forwarding functions do not need one assigned. If a node's node-ID changes, BGP messages must be updated to carry the new ID; upon detecting the change based on the loopback address route, receiving devices update their stored mappings between nodes and node-IDs. Based on the loopback address route and the node-ID, each forwarding node can generate forwarding table entries keyed by the node-ID.

IANA Considerations IANA is requested to allocate a new code points from the "Transitive Opaque Extended Community Sub-Types" registry. TABLE_1

Type	Description	Reference
TBD	Node ID	This Document

Security Considerations This extension to BGP has similar security implications as BGP Extended Communities Attribute .