CCNA IsIs Not covered?

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Quick question, hopefully. I've used Cisco Discovery material to learn material for the CCNA. IsIs gets a one line mention. Just checking, is it no longer part of the CCNA cilibus?

I've got a copy of O'reilly's Cisco Cookbook Second Edition, which is extremely useful but there's not even a chapter on IsIs there either.

 

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Just for info, it's not covered at CCNP either. I think it's been moved to CCIP but not sure.

 

IS IS was in the CCNP until Cisco realised that they where flogging a dead horse and dropped it in the new CCNP ROUTE. Just as well as ISIS is dull beyond human understanding.

 

The very little I know of it. It does sound like a service provider orientated routing protocol.

Just had a bit of an eek moment when I realised I'd not touched it at all.

 

It is very much an ISP protocol, it's very much like OSPF operation, uses Dijkstra's algorithm. It is link state, but is simpler since it is not hierarchal in architecture i.e no concept of every Area must be attached to Area 0.

Rather IS IS uses a distributed backbone architecture where Area 0 is called Level 2 and non backbone Areas are called Level 1.

Other distinctions with OSPF are that in IS IS a router can is in one area and the links are in different areas, unlike OSPF where the router can be in multiple areas. What this means is that area boundaries fall on the links in IS IS.

IS IS also uses it’s own addressing scheme called CLNS which is very scalable if I remember correctly can run up to 20 bytes long.

IS IS uses cost as it’s metric, but on cisco devices the metric is 10 no matter what the interface type is so you always had to go into the interface to tweak the cost to reflect the bandwidth.

Right I am stopping there as I once vowed never to discuss IS IS ever again and I find myself going into teaching mode....damned those pesky kids!!!!