Removing Route Flap Dampening - Foundry Networks Switch and Router Installation And Configuration Manual

Foundry Switch and Router Installation and Configuration Guide
• If you close a neighbor session, the Layer 3 Switch and the neighbor clear all the routes they learned from
each other. When the Layer 3 Switch and neighbor establish a new BGP4 session, they exchange route
tables again. Use this method if you want the Layer 3 Switch to relearn routes from the neighbor and resend
its own route table to the neighbor.
• If you use the soft-outbound option, the Layer 3 Switch compiles a list of all the routes it would normally send
to the neighbor at the beginning of a session. However, before sending the updates, the Foundry Layer 3
Switch also applies the filters and route maps you have configured to the list of routes. If the filters or route
maps result in changes to the list of routes, the Layer 3 Switch sends updates to advertise, change, or even
withdraw routes on the neighbor as needed. This ensures that the neighbor receives only the routes you
want it to contain. Even if the neighbor already contains a route learned from the Layer 3 Switch that you later
decided to filter out, using the soft-outbound option removes that route from the neighbor.
You can specify a single neighbor or a peer group.
USING THE CLI
To close a neighbor session and thus flush all the routes exchanged by the Layer 3 Switch and the neighbor, enter
the following command:
BigIron# clear ip bgp neighbor all
Syntax: clear ip bgp neighbor all | <ip-addr> | <peer-group-name> | <as-num> [soft-outbound | soft [in | out]]
The all | <ip-addr> | <peer-group-name> | <as-num> specifies the neighbor. The <ip-addr> parameter specifies a
neighbor by its IP interface with the Layer 3 Switch. The <peer-group-name> specifies all neighbors in a specific
peer group. The <as-num> parameter specifies all neighbors within the specified AS. The all parameter specifies
all neighbors.
To resend routes to a neighbor without closing the neighbor session, enter a command such as the following:
BigIron# clear ip bgp neighbor 10.0.0.1 soft out
USING THE WEB MANAGEMENT INTERFACE
To resend route information to a neighbor, use the following procedure:
1. Log on to the device using a valid user name and password for read-write access. The System configuration
panel is displayed.
2. Click on the plus sign next to Command in the tree view to expand the list of command options.
3. Click on the Clear link to display the Clear panel.
4. Select BGP Neighbor Soft-Outbound.
5. Use the default value All to resend the BGP4 route table to all neighbors or select a neighbor from the field's
pulldown menu.
6. Click the Apply button to implement the change.

Removing Route Flap Dampening

You can un-suppress routes by removing route flap dampening from the routes. The Layer 3 Switch allows you to
un-suppress all routes at once or un-suppress individual routes.
To un-suppress routes, use either of the following methods.
USING THE CLI
To un-suppress all the suppressed routes, enter the following command at the Privileged EXEC level of the CLI:
BigIron# clear ip bgp damping
Syntax: clear ip bgp damping [<ip-addr> <ip-mask>]
The <ip-addr> parameter specifies a particular network.
The <ip-mask> parameter specifies the network's mask.
19 - 122 December 2000