IS-IS Required Information¶

Before starting, gather all of the information IS-IS requires to form an adjacency with neighbors. At a minimum, TNSR will need to know these items:

VRF Name:: The name of the Virtual Routing and Forwarding instance for which this IS-IS instance will manage routes, or default for the default route table.
Network Entity Title (NET):: Each router requires a unique Network Entity Title (NET) to identify itself among all routers on the network. The NET is composed of several pieces: Authority and Format Identifier (AFI), Area ID, System ID, and Network Selector (NSEL).

See also

Refer to Network Entity Title (NET) for details on these items and how to form a complete NET value.
IS-IS Active Interfaces:: The interfaces on this router upon which the IS-IS daemon will advertise itself and look for neighbors. These interfaces are connected to network segments with other routers. They may be connected to local networks or remote point-to-point links. These interfaces must be configured with IP addresses.

Warning

Due to the fact that IS-IS operates at L2, active interfaces must be interfaces which can carry L2 information. Currently this is limited to Ethernet interfaces as well as GRE interfaces in Transparent Ethernet Bridging (TEB) mode.
IS-IS Passive Interfaces:: These interfaces contain networks which IS-IS will advertise as reachable through this router, but do not contain other routers.

Note

If any loopback interfaces are configured in IS-IS, they can only be passive interfaces.

The example in this section uses the following values: