Concept Guide

neighbor 50.0.0.2 no shutdown
exit-address-family
!
address-family ipv4 multicast vrf vrf1
neighbor 50.0.0.2 activate
exit-address-family
!
address-family ipv6 unicast vrf vrf1
neighbor 50.0.0.2 activate
exit-address-family
DellEMC#
Route-refresh and Soft-reconguration
BGP soft-reconguration allows for faster and easier route changing.
Changing routing policies typically requires a reset of BGP sessions (the TCP connection) for the policies to take eect. Such resets cause
undue interruption to trac due to hard reset of the BGP cache and the time it takes to re-establish the session. BGP soft recong allows
for policies to be applied to a session without clearing the BGP Session. Soft-recong can be done on a per-neighbor basis and can either
be inbound or outbound.
BGP soft-reconguration clears the policies without resetting the TCP connection.
To reset a BGP connection using BGP soft reconguration, use the clear ip bgp command in EXEC Privilege mode at the system
prompt.
When you change the BGP inbound policy locally, you need to process the updates received from a peer. The route refresh capability allows
the local peer to reset inbound information dynamically by exchanging route refresh requests to supporting peers. When an inbound policy
conguration is changed, then the Dell EMC Networking OS sends a refresh request message asking the peer to re-advertise updates.
Upon receiving the refresh request, the peer advertises the required information after applying the outbound lters. Route-refresh is
negotiated during the BGP session establishment and will be used only if both the BGP peers support this capability.
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 following message displays:
Received route refresh capability from peer.
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.
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Border Gateway Protocol (BGP)