From: Chris Lewis (chrlewiscsco@yahoo.com)
Date: Mon Oct 31 2005 - 10:15:12 GMT-3
The discard route could cause a problem like this.
R1-----------R2-------------R3-------R4
All routers have /24 loopbacks 150.1.1.1 150.1.2.2 150.1.2.3.3 and 150.1.4.4
The links between the routers are in a different major network, say 162.8.0.0
R2 is configured (with whatever protocol you like) to send a summary for 150.1.0.0 to R1 that generates a discard route locally.
If we have R2 and R3 in a totally stubby area, with R3 as the ABR, R2 will end up with a default that would normally be used to get to the 150.1.4.4 loopback of R4. However with the local summary to null0 for the 150.1.0.0 network on R2, that becomes the longest match in the routing table and any attempt to ping the loopback of R4 from R2 fails, as the route to null0 wins over the default route.
Tough to explain in a mail, much better on a whiteboard, but did that make sense?
Chris
kevin gannon <kevin@gannons.net> wrote:
I dont see a way of doing this but I am not sure why
it should be a problem ?
You should have other more specific routes to things
that you can reach within the summary.
Maybe you can explain the topology/issue ?
Regards
Kevin
On 10/31/05, Chacko, Raj wrote:
> Hi,
>
> I've searched high and low and am not able to find a mechanism to get rid of
> the discard route installed by ISIS. Does anyone know how to get rid of
> this,
>
> Thanks,
>
> Raj
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
This archive was generated by hypermail 2.1.4 : Sun Nov 06 2005 - 22:00:55 GMT-3