Hi, I am trying to monitor an IS-IS network using BGP-LS to receive the network topology. In IS-IS the LSP typically contains a routerIP entry that provides a IP address on the device the LSP is about. This is useful when monitoring the network as it provides an IP that can be queried with SNMP for more information about the given router. In BGP-LS the RFCs show that there is a Node attribute for the IPv4 address/ID of a router, but this is not populated when distributing an IS-IS network (cisco router sending BGP-LS). Is there a known way to configure a router to provide an IP address as part of the BGP-LS node attributes when distributing IS-IS linkstate? My BGP-LS setup involves a cisco ISIS network with 1 router per area, configured with bgp-ls, peered with frr such that frr will receive the BGP-LS messages (but not do anything with them) Currently my solution involves looking at the advertised prefixes. Prefixes with a IS-IS level of 1, and a /32 mask are an IP address that exists on the named router and can be pinged or queried with SNMP. This works until we encounter a L2-only IS-IS router, as the level2 advertised prefixes can exist from any other router in the area, not just interfaces on the device. A potential workaround for this issue with the l2-only routers I think is to check for the prefix with the lowest metric cost and use that one, though this runs the risk of a local /32 prefix being configured with a higher cost than the links + a neighbors /32 (is this something that would realistically happen?) and choosing the wrong IP address. Are there any potential issues with that solution? Thanks, Colin