Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 228)

Syntax: [no] poison-local-routes
Suppressing RIP route advertisement on a VRRP or VRRPE backup
interface
NOTE
This section applies only if you configure the device for Virtual Router Redundancy Protocol (VRRP) or
VRRP Extended (VRRPE).
Normally, a VRRP or VRRPE Backup includes route information for the virtual IP address (the backed
up interface) in RIP advertisements. As a result, other routers receive multiple paths for the backed up
interface and might sometimes unsuccessfully use the path to the Backup rather than the path to the
Master.
You can prevent the backups from advertising route information for the backed up interface by
enabling suppression of the advertisements.
To suppress RIP advertisements for the backed up interface, enter the following commands.
device(config)# router rip
device(config-rip-router)# use-vrrp-path
Syntax: [no] use-vrrp-path
The syntax is the same for VRRP and VRRP-E.
Configuring RIP route filters using prefix-lists and route maps
You can configure prefix lists to permit or deny specific routes, then apply them globally or to individual
interfaces and specify whether the lists apply to learned routes (in) or advertised routes (out).
You can configure route maps to permit or deny specific routes, then apply a route map to an
interface, and specify whether the map applies to learned routes (in) or advertised routes (out).
NOTE
A route is defined by the destination’s IP address and network mask.
NOTE
By default, routes that do not match a prefix list are learned or advertised. To prevent a route from
being learned or advertised, you must configure a prefix list to deny the route.
To configure a prefix list, enter commands such as the following.
device(config)# ip prefix-list list1 permit 10.53.4.1 255.255.255.0
device(config)# ip prefix-list list2 permit 10.53.5.1 255.255.255.0
device(config)# ip prefix-list list3 permit 10.53.6.1 255.255.255.0
device(config)# ip prefix-list list4 deny 10.53.7.1 255.255.255.0
The prefix lists permit routes to three networks, and deny the route to one network.
Because the default action is permit, all other routes (routes not explicitly permitted or denied by the
filters) can be learned or advertised.
Syntax: [no] ip prefix-list name {permit | deny} {source-ip-address | any source-mask | any}
Suppressing RIP route advertisement on a VRRP or VRRPE backup interface
228 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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