Configuring bgp4 null0 routing, Configuration steps – Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) User Manual
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Multi-Service IronWare Routing Configuration Guide
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Filtering
Syntax: [no] graceful-restart restart-time seconds
The seconds variable sets the maximum restart wait time advertised to neighbors. Possible values
are 1 - 3600 seconds. The default value is 120 seconds.
Configuring BGP4 Restart stale routes timer
Use the following command to specify the maximum amount of time a helper device will wait for an
end-of-RIB message from a peer before deleting routes from that peer.
Brocade(config-bgp)# graceful-restart stale-routes-time 120
Syntax: [no] graceful-restart stale-routes-time seconds
The seconds variable sets the maximum time before a helper device cleans up stale routes.
Possible values are 1 - 3600 seconds. The default value is 360 seconds.
Configuring BGP4 Restart purge timer
Use the following command to specify the maximum amount of time a device will maintain stale
routes in its routing table before purging them.
Brocade(config-bgp)# graceful-restart purge-time 900
Syntax: [no] graceful-restart purge-time seconds
The seconds variable sets the maximum time before a restarting device cleans up stale routes.
Possible values are 1 – 3600 seconds. The default value is 600 seconds.
For information about displaying BGP4 restart neighbor information, refer to
Configuring BGP4 null0 routing
BGP4 null0 routing is described in
on page 13. The following example
configures a null0 routing application to stop denial of service attacks from remote hosts on the
Internet.
Configuration steps
1. Select a device, for example, device 6, to distribute null0 routes throughout the BGP4 network.
2. Configure a route-map to match a particular tag (50) and set the next-hop address to an
unused network address (192.168.0.1).
3. Set the local-preference to a value higher than any possible internal or external
local-preference (50).
4. Complete the route map by setting origin to IGP.
5. On device 6, redistribute the static routes into BGP4, using route-map route-map-name
(redistribute static route-map block user).
6. On device 1, (the device facing the Internet), configure a null0 route matching the next-hop
address in the route-map (ip route 192.168.0.1/32 null0).
7. Repeat step 3 for all devices interfacing with the Internet (edge corporate devices). In this
case, device 2 has the same null0 route as device 1.