Hi, On ven. 20 déc. 22:36:29 2019, Nico Schottelius wrote:
Hello,
I was wondering about how bird solves the following problem with next hop self enabled:
R1 <--------> R2 \ / \ / upstream 1
So both routers receive the same routes from upstream and insert them with the same local_pref. With "next hop self" on, both routers will think that the path is not the same and potentially either of the two routers could start routing via the other router instead of via upstream directly.
What is the typical approach to solve this situation correctly? Does making setting the local_pref lower if received from an iBGP router make sense in that case?
Best regards,
Nico
There will be no loop because eBGP paths are preferred over iBGP ones if the routes are equals. https://tools.ietf.org/html/rfc1771#section-9.1 BTW, using classical iBGP, RRs and an IGP will solve many of this kind of problems. -- Alarig