[c-nsp] ASR920 Opinions

[Mark Tinka]

On 22/Dec/17 13:13, Spyros Kakaroukas wrote:

> Hello,
>
> We've also been doing something similar for about a year now, and we're pretty happy with it. We're only installing defaults ( pointing towards large boxes that do install the full table ) , prefixes originated inside our own AS ( could probably divide those to multiple hierarchies, but they're not that many at the moment ) and eBGP customer prefixes.

This is a good point to note.

In that document, I simplified the configuration to keep it generalized.
But one thing you want to note is that if you run the ASR920's in a
ring, and you have IP customers hanging off each device in the ring, you
want to maintain shortest-path at all times, or else traffic between
devices in the same ring could exit the ring only come back.

In the example, you can expand the match conditions for the Table Map
feature in the Route Map to search specific prefixes (best done via BGP
communities) that are within the same Metro-E ring. That way, BGP-SD
installs those routes into FIB so that routing happens locally within
the ring.

Mark.