Connectivity Guide
neighbor 32.1.1.2
remote-as 103
timers 61 181
no shutdown
Neighbor soft-reconguration
BGP soft-reconguration allows for fast and easy route changes. Changing routing policies requires a reset of BGP sessions or the TCP
connection, for the policies to take eect.
Resets cause undue interruption to trac due to the hard reset of the BGP cache, and the time it takes to re-establish the session. BGP
soft-reconguration allows for policies to apply to a session without clearing the BGP session. You can perform a soft-reconguration on a
per-neighbor basis, either inbound or outbound. BGP soft-reconguration clears the policies without resetting the TCP connection. After
conguring soft-reconguration, use the clear ip bgp command to make the neighbor use soft reconguration.
When you enable soft-reconguration for a neighbor and you execute the clear ip bgp soft in command, the update database
stored in the router replays and updates are re-evaluated. With this command, the replay and update process triggers only if a route-refresh
request is not negotiated with the peer. If the request is negotiated after using the clear ip bgp soft in command, BGP sends a
route-refresh request to the neighbor and receives all the peer’s updates.
To use soft reconguration, or soft reset without preconguration, both BGP peers must support soft route refresh. The soft route refresh
advertises in the OPEN message sent when the peers establish a TCP session. To determine whether a BGP router supports this capability,
use the show ip bgp neighbors command. If a router supports the route refresh capability, the Received route refresh
capability from peer
message displays.
1 Enable soft-reconguration for the BGP neighbor and BGP template in ROUTER-BGP mode. BGP stores all the updates that the
neighbor receives but does not reset the peer-session. Entering this command starts the storage of updates, which is required to do
inbound soft reconguration.
neighbor {ip-address} soft-reconfiguration inbound
2 Enter Address Family mode in ROUTER-NEIGHBOR mode.
address-family {[ipv4 | ipv6] [unicast]}
3 Congure soft-conguration for the neighbors belonging to the template.
soft-reconfiguration inbound
4 Clear all information or only specic details in EXEC mode.
clear ip bgp {neighbor-address | * } [soft in]
• * — Clears all peers.
• neighbor-address — Clears the neighbor with this IP address.
Soft-reconguration of IPv4 neighbor
OS10(conf-router-neighbor)# address-family ipv4 unicast
OS10(conf-router-bgp-neighbor-af)# soft-reconfiguration inbound
Soft-reconguration of IPv6 neighbor
OS10(conf-router-neighbor)# address-family ipv6 unicast
OS10(conf-router-bgp-neighbor-af)# soft-reconfiguration inbound
BGP commands
Layer 3
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