Re: Conditional ISIS default route advertisement

Try using a prefix-list to match the route, and a standard ACL to
match the next-hop.

ip prefix-list default permit 0.0.0.0/0
access-list 1 permit 3.3.3.3

route-map conditional permit 10
 match ip address prefix-list default
 match ip next-hop 1

-Yuri

On Tue, Jul 31, 2012 at 7:09 PM, John Neiberger <jneiberger_at_gmail.com> wrote:
> I'm toying around with conditional default advertisement in ISIS and I just
> can't get it tuned right. A router, let's call it R2, has an eBGP peer and
> another "internal" peer and it's learning a default from both. I'm trying
> to configure R2 such that it only advertises a default if it is learning it
> from its eBGP peer. The problem I'm having is that no matter how I've
> configured it, whenever I add a route map to the default-information
> originate command, it just stops advertising the default. I haven't found
> any example configurations, so I really don't know how to craft the route
> map. I've tried matching the next hop of the route and I've tried using an
> ACL, but neither is working.
>
> The eBGP peer is 3.3.3.3. This is the first route map I tried:
>
> route-map ISIS_DEFAULT permit 10
> match ip next-hop 3.3.3.3
>
> That didn't work at all. I was hoping it would match on the route in the
> routing table, but it didn't seem to work at all. So, I tried this:
>
> access-list 100 permit 0.0.0.0 0.0.0.0 3.3.3.3 0.0.0.0
>
> route-map ISIS_DEFAULT
> match ip address 100
>
> I thought that would look for a 0.0.0.0 route in the table with a next-hop
> of 3.3.3.3, but that didn't work either. It's been a LONG time since I've
> done anything like this. Please refresh my memory. :)
>
> I'm sure I'm missing something obvious, but what is it?
>
> Thanks,
> John
>
>
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Received on Tue Jul 31 2012 - 21:21:41 ART