IS-IS multi-area but all level-2 only - Any benefits?

[smailmilak]

Hello,

quick question about IS-IS and multi-area (49.0001, 49.0002, 49.0003 etc.) but all nodes are L2.

Does this bring any benefits in terms of smaller LSDB, scalability etc.?

[balaji.bandi]

It all depends on how the they connected - required some topology to understand with that output we can can say how is your network.

refer below document :

https://www.cisco.com/c/en/us/support/docs/ip/integrated-intermediate-system-to-intermediate-system-is-is/200293-IS-IS-Adjacency-and-Area-Types.html

[smailmilak]

Hi,

no need for a topo. It's a regular network with P and PE nodes. Around 20 in Core, and 10 in each PE ring. Each PE ring connected to P ring only.

I ask myself if the LSDB will be smaller with multi-area but all L2 nodes. By my understanding it would be the same. I have checked the document you have provided before but no clear answer.

[Abzal]

Hi,

The main benefit is MPLS-TE tunnels because PE will have the whole topology visibility and not only own area topology to be able to build end to end tunnels.