Then simply put a static route on ISP B router to point 100.0.0.0/8 to the ISP A router. If ISP B goes down, it stops advertizing the default route, and things kick over to ISP A, which needs no ...

IPv6 configuration follows some of these same guidelines, with the largest difference being how to enable a routing protocol on an interface. Cisco router IOS does not enable IPv6 routing by ...