[c-nsp] VRF randomly, stably install only one from multiple route sets

[Everton da Silva Marques]

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.

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.