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Confederations

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You can clear the BGP connection of a peer on any BGP router using the clear

ip bgp peer-group peer-group-name

command in Privilege mode.

Multi-homing

Multi-homing is the process of connecting two or more service providers to
one network in an effort to provide redundancy to the outside world. Multi-
homing can be used with or without BGP. If you are not using BGP, you can
use default routes. Default routes must be manually configured on a router.
Remember, a manually configured route is a static route. BGP finds its own
routes, and the routes do not need to be manually configured. These routes
are called dynamic routes when the administrator does not need to manually
configure them. Static routes can be configured with BGP; regardless of
whether BGP knows a better route through the network, it will use the static
route. BGP does this by trusting a static route more than a route that it has
learned itself.

Static routes give only the interface of the destination for the next hop.

BGP learns the entire route from one point to another.

Using default static routes relieves the processor on the router from handling

BGP processes that tax the processor heavily. It also frees RAM in the router

for other uses.

In the example below, BGP is not configured. We use the ip route com-

mand followed by 0.0.0.0, which means any destination IP address; the
second 0.0.0.0 indicates any mask the router doesn't know about from the
IGP. In this case, we use OSPF as the IGP. We then use the default-
information orginate always

command to instruct all the other OSPF

routers to learn this default route. Figure 9.4 shows our network using a
single static route.

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