Suppressing Rip Route Advertisement On Avrrp Or Vrrpe Backup Interface; Configuring Rip Route Filters - Foundry Networks FESX Manual

Configuring RIP
FastIron SuperX Router(config-if-1/1)# no ip rip poison-reverse
Syntax: [no] ip rip poison-reverse
To disable split horizon and enable poison reverse on an interface, enter commands such as the following:
FastIron SuperX Router(config)# interface ethernet 1/1
FastIron SuperX Router(config-if-1/1)# ip rip poison-reverse
Suppressing RIP Route Advertisement on a VRRP or VRRPE Backup Interface
NOTE: This section applies only if you configure the Layer 3 Switch for Virtual Router Redundancy Protocol
(VRRP) or VRRP Extended (VRRPE). See "Configuring VRRP and VRRPE" on page 22-1.
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:
FastIron SuperX Router(config)# router rip
FastIron SuperX Router(config-rip-router)# use-vrrp-path
Syntax: [no] use-vrrp-path
The syntax is the same for VRRP and VRRPE.

Configuring RIP Route Filters

You can configure RIP route filters to permit or deny learning or advertising of specific routes. Configure the filters
globally, then apply them to individual interfaces. When you apply a RIP route filter to an interface, you specify
whether the filter 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 route filter are learned or advertised. To prevent a route from being
learned or advertised, you must configure a filter to deny the route.
To configure RIP filters, enter commands such as the following:
FastIron SuperX Router(config-rip-router)# filter 1 permit 192.53.4.1 255.255.255.0
FastIron SuperX Router(config-rip-router)# filter 2 permit 192.53.5.1 255.255.255.0
FastIron SuperX Router(config-rip-router)# filter 3 permit 192.53.6.1 255.255.255.0
FastIron SuperX Router(config-rip-router)# filter 4 deny 192.53.7.1 255.255.255.0
These commands explicitly permit RIP routes to three networks, and deny the route to one network.
Since the default action is permit, all other routes (routes not explicitly permitted or denied by the filters) can be
learned or advertised.
Syntax: filter <filter-num> permit | deny <source-ip-address> | any <source-mask> | any [log]
Applying a RIP Route Filter to an Interface
Once you define RIP route filters, you must assign them to individual interfaces. The filters do not take effect until
you apply them to interfaces. When you apply a RIP route filter, you also specify whether the filter applies to
learned routes or advertised routes:
• Out filters apply to routes the Layer 3 Switch advertises to its neighbor on the interface.
December 2005 © Foundry Networks, Inc. 17 - 9