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DIS router

auos

Hi,

I am not understanding what is the benefit of (DIS router) in IS-IS if All physical routers still
establish adjacency to each other, it is mean there is no reducing for LSP traffic because it is just a Pseudonode and Logically connected to all other nodes.

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Comments

georgemc

Try here:

Understanding IS-IS Pseudonode LSP [IP Routing] - Cisco Systems

fonque

if i understand correctly the DIS reduces traffic of lsdb synchronization.
example with 5 routers on a LAN, all L1 or all L2,

instead of 10 adjacencies, each with 2 routers synchronizing and updating each other,
you only have 5 adjacencies with the psuedonode, and only the DIS is sending out a pseudonode lsp representing the whole network, instead of all of the them.

billscott92787

georgemc wrote: »

Try here:

Understanding IS-IS Pseudonode LSP [IP Routing] - Cisco Systems

Check out the link that George posted, it shows you the purpose of it there. "One is that the DIS is responsible for flooding LSPs over the LAN. As well as creating and maintaining LSPs for the pseudonode for reporting links to all systems on the broadcast subnetwork."