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
