Concept Guide

– 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.
If neighbor soft-reconfiguration inbound command is not congured ever in the router, then doing a soft reset is enough for
the route refresh updates to be sent.
Route-refresh updates for IPv4 and IPv6 prexes
This section explains the route-refresh functionality in dierent combinations for IPv4 or IPv6 prex congured with IPv4 or IPv6
neighbors.
By default, the IPv4 prexes is sent for all the neighbors irrespective of IPv4 address family is enabled or disabled. Following are the
dierent scenarios during which the route-refresh message is sent for the corresponding neighbors:
By default, the route-refresh message for IPv4 prexes is sent for both the IPv4 and IPv6 neighbors. Following is an example conguration
in which IPv4 prexes are enabled by default and the corresponding route-refresh message:
DellEMC(conf-router_bgp)# show config
!
router bgp 100
redistribute connected
neighbor 20.1.1.2 remote-as 200
neighbor 20.1.1.2 no shutdown
neighbor 20::2 remote-as 200
neighbor 20::2 no shutdown
!
address-family ipv6 unicast
Border Gateway Protocol (BGP)
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