Default Route from BGP to OSPF

RouterOS Forwarding Protocols
13

Imho, do a iBGP session between your various BGP routers to distribute the default route received from your upstream providers. In the BGP peer config, set “nexthop choice” to “force self” and “default originate” to “if installed”

Then configure the OSPF sessions on those routers to redistribute default route “always as type-1”.

That way:

  1. The routers will always distribute their default route by OSPF (if they have one)
  2. If a router lose its upstream connection, it will still receive a default route from one of the other router through the iBGP session.