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New Member

Interface on two IS-IS areas?

Hi

I´ve read that an interface can not be speaking in more than one ISIS area, and that is possible that a WAN interface can speak in more than one ISIS area using sub-interfaces, a sub-interface per IS-IS area.

Does anyone know if this is valid for LAN interfaces too?

I´m trying to configure a router that be able to speak in two ISIS areas using just one physical interface.

Thanks in advance!

Hugo.

2 REPLIES
Gold

Re: Interface on two IS-IS areas?

The only way to run a single interface in two areas is to merge the areas, which effectively makes them one area. In other words, you can't do this. :-) It's a matter of packet formatting, etc. There are no interior gateway routing protocols that can do this.

You can create subinterfaces, using vlans, and put each one in a seperate interface, but then again, that's not running a single interface in multiple areas, that's running multiple logical interfaces on the same physical interface.

:-)

Russ.W

New Member

Re: Interface on two IS-IS areas?

Thanks Russ, your comments were very helpful!

Hugo.

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