[c-nsp] BGP-ORR vRR/IOS-XRv

[adamv0025 at netconsultings.com]

> Curtis Piehler
> Sent: Wednesday, March 21, 2018 10:57 PM
> 
> Thank you, with the general RR concerns out of the way I'd like to hear if
> anyone has specific BGP ORR experience in an IOS-XRv environment.
> 
I was only evaluating it as a solution for limiting advertisement of
superfluous copies of transit prefixes in Internet VRF.
The requirements:
1) one primary path and one backup path
2) complete freedom in primary path engineering (per-group/per-node)
3) complete freedom in backup path engineering (per-group/per-node)

And requirement 3 was not met with current ORR implementations, you can't
select ORR backup path, the backup path selection is governed by the
Add-Path which does not have the "2nd IGP best path" knowledge allowing it
to pick the desired backup path.

The solution was to use the good old type-1 RDs and Route-Targets to allow
for complete freedom in AS-Exit engineering.  

adam

netconsultings.com
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