Concept Guide

If you specify a BGP peer group by using the peer-group-name argument, all members of the peer group inherit the characteristic
congured with this command.
• Enable soft-reconguration for the BGP neighbor specied.
CONFIG-ROUTER-BGP mode
neighbor {ip-address | ipv6-address | peer-group-name} soft-reconfiguration inbound
BGP stores all the updates received by the neighbor but does not reset the peer-session.
Entering this command starts the storage of updates, which is required to do inbound soft-reconguration. Outbound BGP soft-
reconguration does not require inbound soft-reconguration to be enabled.
• Reset BGP connection using soft-reconguration.
EXEC Privilege mode
clear ip bgp [vrf vrf-name] [* | neighbor-address | as-number | ipv4 | ipv6 | peer-group-name
| dampening | flap-statistics] {soft {in | out}}
– *: Clears all peers.
– neighbor-address: Clears the IPv4 or IPv6 neighbor of this IP address.
– as-number: Clears the peers AS numbers.
– ipv4: Clears information for the IPv4 address family.
– ipv6: Clears information for the IPv6 address family.
– peer-group-name: Clears all members of the specied peer group.
– dampening: Clears all the ap dampening information.
– flap-statistics: Clears the ap statistics information.
Example of Soft-recongration of a BGP Neighbor
The example enables inbound soft-reconguration for the neighbor 10.108.1.1. All updates received from this neighbor are stored unmodied,
regardless of the inbound policy. When inbound soft-reconguration is done later, the stored information is used to generate a new set of
inbound updates
DellEMC(conf)# router bgp 100
DellEMC(conf-router_bgp)# neighbor 10.108.1.1 remote-as 20
DellEMC(conf-router_bgp)# neighbor 10.108.1.1 soft-reconfiguration inbound
DellEMC(conf-router_bgp)# exit
Route-refresh
This section explains how the soft-reconguration and route-refresh works. Soft-reconguration has to be congured explicitly for a
neighbor unlike route refresh, which is automatically negotiated between BGP peers when establishing a peer session.
The route-refresh updates will be sent, only if the neighbor soft-reconfiguration inbound command is not congured in a
BGP neighbor and when you do a soft reset using clear ip bgp {neighbor-address | peer-group-name} soft in
command.
If the neighbor soft-reconfiguration inbound is already congured in the BGP neighbor, the route refresh updates will not be
sent. If you want to use route refresh updates instead, remove the neighbor soft-reconfiguration inbound conguration and
then you need to do a hard reset atleast once, using clear ip bgp {* | as-number | ipv4| ipv6 | neighbor-address
| peer-group-name} command. If you remove neighbor soft-reconfiguration inbound for an individual neighbor (not
part of peer-group), then doing hard reset for the individual neighbor is enough. If the neighbor is part of a peer-group and when
neighbor soft-reconfiguration inbound is removed from the peer group, we need to do a hard reset for the peer-group.
Border Gateway Protocol (BGP)
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