[j-nsp] IS-IS not installing route into RIB

Pedro Antunes pedro.mantunes at sapo.pt
Thu Apr 30 06:51:50 EDT 2015


You have to look first at the IS-IS database: show isis database detail
For that prefix P, you'll see two routers advertising it, the local router R1
and the remote router R2.
( I assume say that you are advertising these prefixes with the default metric
which is 0. In any case, the explanation would be similar with different
Now it's time to run the SPF algorithm on the local router R1.
So we know P twice:
- local LSP: with metric = 0 and 
- remote LSP: with metric = 0 + cost to reach R2
So SPF elects the local router R1 as the single exit point for this prefix P.
You can see the SPF results with show isis spf results

Now you could also play with the exported metrics on one of the router so that
for one of the router SPF decides to send the traffic to the remote router. Of
course you cannot achieve that on both of them.

In any case, if your goal is to achieve redundancy, you have it even in your
scenario. It happens at the speed of IS-IS reconvergence though.


On Fri, 06 Feb 2015 at 13:29 GMT, Olivier Benghozi <olivier.benghozi at wifirst.fr> wrote:
> Damn, if no one has a clue I guess we're condemned to wait for your JTAC results...

Pedro Marques Antunes

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