BGP4 parameters

Some parameter changes take effect immediately while others do not take full effect until the device sessions with its neighbors are reset. Some parameters do not take effect until the device is rebooted.

The following parameter changes take effect immediately:

• Enable or disable BGP4.
• Set or change the local AS.
• Add neighbors.
• Change the update timer for route changes.
• Disable or enable fast external failover.
• Specify individual networks that can be advertised.
• Change the default local preference, default information originate setting, or administrative distance.
• Enable or disable use of a default route to resolve a BGP4 next-hop route.
• Enable or disable MED (metric) comparison.
• Require the first AS in an update from an EBGP neighbor to be the neighbor AS.
• Change MED comparison parameters.
• Disable comparison of the AS-Path length.
• Enable comparison of the device ID.
• Enable next-hop recursion.
• Change the default metric.
• Disable or re-enable route reflection.
• Configure confederation parameters.
• Disable or re-enable load sharing.
• Change the maximum number of load sharing paths.
• Change other load-sharing parameters.
• Define route flap dampening parameters.
• Add, change, or negate redistribution parameters (except changing the default MED).
• Add, change, or negate route maps (when used by the network command or a redistribution command).
• Apply maximum AS path limit settings for UPDATE messages.
• Aggregate routes
• Add, change, or negate filter tables that affect inbound and outbound route policies.

The following parameter changes take effect only after the BGP4 sessions on the device are cleared, or reset using the "soft" clear option:

• Change the Hold Time or Keep Alive Time.
• Apply maximum AS path limit settings to the RIB.

The following parameter change takes effect only after you disable and then re-enable redistribution:

• Change the default MED (metric).