Connectivity Guide

8 Enable the neighbor in ROUTER-BGP mode.
neighbor ip-address
9 Enable the peer-group in ROUTER-NEIGHBOR mode.
no shutdown
When you add a peer to a peer group, it inherits all the peer group congured parameters. When you disable a peer group, all the peers
within the peer template that are in the Established state move to the Idle state. A neighbor cannot become a part of a peer group if it has
any of these commands congured:
• advertisement-interval
• next-hop-self
• route-map out
• route-reflector-client
• send-community
A neighbor may keep its conguration after it is added to a peer group if the neighbor conguration is more specic than the peer group
and if the neighbor conguration does not aect outgoing updates.
To display the peer-group conguration assigned to a BGP neighbor, enter the show ip bgp peer-group peer-group-name
command. The show ip bgp neighbor command output does not display peer-group congurations.
Congure peer templates
OS10(config)# router bgp 300
OS10(config-router-bgp-300) vrf blue
OS10(config-router-vrf)# template ebgppg
OS10(config-router-template)# remote-as 100
OS10(config-router-template)# description peer_template_1_abcd
OS10(config-router-template)# exit
OS10(config-router-vrf)# neighbor 3.1.1.1
OS10(config-router-neighbor)# inherit template ebgppg
OS10(config-router-neighbor)# no shutdown
Neighbor fall-over
The BGP neighbor fall-over feature reduces the convergence time while maintaining stability. When you enable fall-over, BGP tracks IP
reachability to the peer remote address and the peer local address.
When remote or peer local addresses become unreachable, BGP brings the session down with the peer. For example, if no active route
exists in the routing table for peer IPv6 destinations/local address, BGP brings the session down.
By default, the hold time governs a BGP session. Congure BGP fast fall-over on a per-neighbor or peer-group basis. BGP routers typically
carry large routing tables as frequent session resets are not desirable. If you enable fail-over, the connection to an internal BGP peer is
immediately reset if the host route added to reach the internal peer fails.
1 Enter the neighbor IP address in ROUTER-BGP mode.
neighbor ip-address
2 Disable fast fall-over in ROUTER-NEIGHBOR mode.
no fall-over
3 Enter the neighbor IP address in ROUTER-BGP mode.
neighbor ip-address
4 Enable BGP fast fall-Over in ROUTER-NEIGHBOR mode.
fall-over
Congure neighbor fall-over
OS10(config)# router bgp 100
OS10(config-router-bgp-100)# neighbor 3.1.1.1
Layer 3
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