Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 41)

Multi-Service IronWare Routing Configuration Guide 13
53-1003033-02
BGP4 Restart
FIGURE 4 Example of Local AS configured on ISP-B
A Local AS is configured using the BGP4 neighbor command, as described in “Configuring BGP4
neighbors” on page 47. To confirm that a Local AS has been configured use the show ip bgp
neighbors command, as described in “Displaying BGP4 neighbor information” on page 122.
BGP4 null0 routing
BGP4 considers the null0 route in the routing table (for example, static route) as a valid route, and
can use the null0 route to resolve the next hop. If the next hop for BGP4 resolves into a null0 route,
the BGP4 route is also installed as a null0 route in the routing table.
The null0 routing feature allows network administrators to block certain network prefixes using
null0 routes and route-maps, directing a remote device to drop all traffic for a network prefix by
redistributing a null0 route into BGP4.