[c-nsp] VRF randomly,
stably install only one from multiple route sets
Oliver Boehmer (oboehmer)
oboehmer at cisco.com
Fri Jan 7 18:06:33 EST 2005
everton at lab.ipaccess.diveo.net.br
<mailto:everton at lab.ipaccess.diveo.net.br> wrote on Friday, January 07,
2005 9:06 PM:
> Oliver Boehmer (oboehmer) wrote:
>>
>> You might want to check the "import" option to
>> ibgp-multipath. This way we'll import more paths
>> into the VRF and we can fail-over to alternate
>> paths without waiting for the periodic import-scan.
>
> I have found this:
>
> The import keyword allows the network operator
> to configure the VRF table to accept multiple
> redundant paths in addition to the best path.
> This feature should be used when there are multiple
> paths with identical next hops available to ensure
> optimal convergence times. A typical application of
> this configuration option is to configure redundant
> paths in a network that has multiple route reflectors
> for redundancy.
>
> Would this work for equal prefixes exported from
> VRFs hosted at different PEs? I'm afraid here in
> our case we have mostly different next hops pointing
> to distinct PEs.
It also works in this case, i.e. multiple PE's advertising the same IPv4
prefix with different RD's.
> A difficulty ibgp-multipath-import option does
> not seem to address is the unstable routes R1
> temporarily taking over stable routes R2 as the
> router PE1 oscillates between up and down.
You are right, it only avoids waiting 15 secs for the next import-scan..
oli
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