For reference, NTT publishes their BGP communities... https://us.ntt.net/support/policy/routing.cfm
If Charter were NTT, you'd want something like 2914:460, which sets the local preference to 98, which is lower (worse) than 100, the peer default. So as long as your prefixes were learned by another of their peers, they would ignore your routes. -Kristian On 11/01/2017 12:40 PM, Kristian Hoffmann via Mikrotik-users wrote: > I think the "best" answer lies with BGP communities. What you're > looking for what I've seen called a "backup only" route. You can try > asking Charter support for a list of their supported BGP communities. > The goal would be to announce your prefixes to them with a community > that instructs them to only install and/or advertise your prefixes if > they haven't learned your prefixes from some other source. Every > carrier implements it differently, and some don't at all. Here's a > relatively good article on the subject that's worth reading to > familiarize yourself with the concept... > > https://www.noction.com/blog/understanding_bgp_communities > > Like others have said, there's more than one way to do this, and there's > no right/wrong. Mix into all of that the idea of being a good steward > of the global routing table, and it makes for all sorts of fun. Happy > routing! > > -Kristian > > > On 11/01/2017 06:06 AM, Ethan E. Dee via Mikrotik-users wrote: >> I am multihomed. I have a router that peers with charter and advertises >> a few subnets. (Let's call it C) >> >> I have a router that peers with AT&T at a tower (lets call it A) >> >> And a router that peers with Spirit at a tower (lets call it S) >> >> AT&T seems to have quite a low preference to the world. And I have no >> idea what I'm doing. Though I feel like I do. >> >> Nothing works. >> >> All three routers are mikrotik. How do I tell the world to forget about >> Charters advertisements unless you can no longer see AT&T? >> >> >> >> >> -- >> This message has been scanned by E.F.A. Project and is believed to be clean. >> >> >> _______________________________________________ >> Mikrotik-users mailing list >> [email protected] >> http://lists.wispa.org/mailman/listinfo/mikrotik-users > _______________________________________________ > Mikrotik-users mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/mikrotik-users _______________________________________________ Mikrotik-users mailing list [email protected] http://lists.wispa.org/mailman/listinfo/mikrotik-users
