graceful-restart (BGP)
graceful-restart
[
purge-time
seconds
|
restart-time
seconds
|
stale-routes-time
seconds
]
no graceful-restart
[
purge-time
seconds
|
restart-time
seconds
|
stale-routes-time
seconds
]
Graceful restart is enabled globally.
- purge-time seconds
- Specifies the maximum period of time, in seconds, for which a restarting device maintains stale routes in the BGP routing table before purging them. Range is from 1 to 3600 seconds. The default value through 600 seconds.
- restart-time seconds
- Specifies the restart time, in seconds, advertised to graceful-restart-capable neighbors. Range is from 1 through 3600 seconds. The default value is 120 seconds.
BGP configuration mode
BGP address-family IPv6 unicast configuration mode
Use this command to enable or disable the graceful restart capability globally for all BGP neighbors in a BGP network. If the graceful restart capability is re-enabled after a BGP session has been established, the neighbor session must be cleared for GR to take effect.
When this command is entered in BGP global configuration mode, it applies only to the IPv4 address family. Use this command in BGP address-family IPv6 unicast configuration mode for BGP4+ configurations.
Use this command in BGP configuration mode to disable or re-enable the BGP4 graceful restart capability globally, or to alter the default parameters. Use this command in address-family IPv6 unicast configuration mode to disable or re-enable the BGP4+ graceful restart capability globally or to alter the default parameters.
The purge-time parameter is applicable for both restarting and helper devices. The timer starts when a BGP connection is closed. The timer ends when an EOR is received from all nodes, downloaded into BGP and an EOR sent to all neighbors. The configured purge-time timer value is effective only on the configured node.
The restart-time parameter is applicable only for helper devices. The timer starts at the time the BGP connection is closed by the remote peer and ends when the Peer connection is established. The configured restart time timer value is effective only on the peer node, and not in the configured node. During negotiation time, the timer value is exchanged.
The stale-routes-time parameter is applicable only for helper devices. The timer starts when the peer connection is established once the HA-failover peer node has been established. The timer ends at the time an EOR is received from the peer. The configured stale-time timer value is effective only on the configured node.
Use the
clear ip bgp neighbor command with the
all parameter for the changes to the GR parameters to take effect immediately.
The
no form of the command disables the BGP graceful restart capability globally for all
BGP neighbors.
The following example disables the BGP4 graceful restart capability.
device# configure terminal device(config)# router bgp device(config-bgp-router)# no graceful-restart
The following example re-enables the BGP4 graceful restart capability.
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1 device(config-bgp-router)# neighbor 1.1.1.1 remote-as 2 device(config-bgp-router)# graceful-restart
The following example disables the BGP4+ graceful restart capability.
device# configure terminal device(config)# router bgp device(config-bgp-router)# address-family ipv6 unicast device(config-bgp-ipv6u)# no graceful-restart
The following example re-enables the BGP4+ graceful restart capability.
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1 device(config-bgp-router)# neighbor 1000::1 remote-as 2 device(config-bgp-router)# address-family ipv6 unicast device(config-bgp-ipv6u)# neighbor 1000::1 activate device(config-bgp-ipv6u)# graceful-restart
The following example sets the purge time to 240 seconds at the IPv4 address family configuration level.
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1 device(config-bgp-router)# neighbor 1.1.1.1 remote-as 2 device(config-bgp-router)# graceful-restart %Warning: Please clear the neighbor session for the parameter change to take effect! device(config-bgp-router)# graceful-restart purge-time 240
The following example sets the restart time to 60 seconds at the IPv4 address family configuration level.
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1 device(config-bgp-router)# neighbor 1.1.1.1 remote-as 2 device(config-bgp-router)# graceful-restart %Warning: Please clear the neighbor session for the parameter change to take effect! device(config-bgp-router)# graceful-restart restart-time 60 %Warning: Please clear the neighbor session for the parameter change to take effect!
The following example sets the stale-routes time to 180 seconds at the IPv6 address family configuration level.
device# configure terminal device(config)# router bgp device(config-bgp-router)# local-as 1 device(config-bgp-router)# neighbor 1000::1 remote-as 2 device(config-bgp-router)# address-family ipv6 unicast device(config-bgp-ipv6u)# neighbor 1000::1 activate device(config-bgp-ipv6u)# graceful-restart %Warning: Please clear the neighbor session for the parameter change to take effect! device(config-bgp-ipv6u)# graceful-restart stale-routes-time 180 %Warning: Please clear the neighbor session for the parameter change to take effect!