Tuesday, October 5, 2021

eBGP routing question

Hi folks, I have a pretty basic question regarding how BGP works. I think I understand the fundamental princilples, but what I don't understand is why every router needs to see all routes, and how this information is actually used to make routing desisions.

I guess my main question is, does every participating BGP router have it's own routing table which BGP creates using data that is shared from it's peers? why does every router need to know about every prefix/route? is this so it can use the info to build it's own routing table?

For example, say i am a eBGP router (ASN 0) connected to 2 other ASNs : ASN 1 and ASN 2

I only have two possible routes to send traffic out, does BGP take the info shared with it for all possible routes/prefixes and then create a dedicated routung table just for me (ASN 0), so that I know which of the two ASNs directly connected to forward my traffic to?



No comments:

Post a Comment