[c-nsp] BGP Route Announcement

Mark Tinka mark.tinka at seacom.mu
Fri Dec 14 12:32:22 EST 2018



On 14/Dec/18 19:16, Joseph Mays wrote:

>
> The distribute lists shown also just contained appropriate permit and deny entries for 216.24.0.0 /18

Firstly, please don't use distribute lists. This is very archaic and
prone to mistakes. Suggest you migrate to prefix lists right away!

>
>
> That changed the broadcast cogent was receiving, but not in the expected way. They only route they saw us broadcasting after that was the 216.24.60.0/23 route. Not the first one in the list, not the last one, not the biggest one or the smallest one, but just one route from the middle of the list. I don't get this behavior at all. Cogent cleared and bounced bgp to us, and still received only that one route in the broadcast from us.

After you've fixed your filtering with prefix lists, you need to ensure
that any "network..." statement is backed up by the presence of the very
same route in your IGP (which includes static routing).

Mark.


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