Setup Guide

Table Of Contents
NOTE: If you enter a 4-byte AS number, 4-byte AS support is enabled automatically. This command is optional. Use it
only if you support 4-Byte AS numbers or if you support AS4 number representation.
Disable 4-Byte support and return to the default 2-Byte format by using the no bgp four-octet-as-support
command. You cannot disable 4-Byte support if you currently have a 4-Byte ASN configured.
DellEMC# configure terminal
DellEMC(conf)# router bgp 80000
DellEMC(conf-router_bgp)# bgp four-octet-as-support
DellEMC(conf-router_bgp)# neighbor 20.20.20.1 remote-as 200
DellEMC(conf-router_bgp)# neighbor 20.20.20.1 no shutdown
DellEMC(conf-router_bgp)#exit
To view BGP configuration, use the show running-config bgp command in EXEC Privilege mode.
The following example shows the show ip bgp summary command output (4byte AS number displays).
R2#show ip bgp summary
BGP router identifier 1.1.1.1, local 80000
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
1 neighbor(s) using 40960 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 200 0 0 0 0 0 00:00:00 0
Changing a BGP router ID
BGP uses the configured router ID to identify the devices in the network.
By default, the router ID is the highest IP address of the Loopback interface. If no Loopback interfaces are configured, the
highest IP address of a physical interface on the router is used as the BGP router ID. To change the default BGP router ID, use
the following command.
Change the BGP router ID of a BGP router
ROUTER BGP mode
bgp router-id ip-address
ip-address- IP address in dotted decimal format.
NOTE: Do not specify an IP address which is used by another device as a router ID.
Peering sessions are reset when you change the router ID of a BGP router. Upon changing the router ID, the system
automatically restarts the BGP instance for the configuration to take effect.
DellEMC# configure terminal
DellEMC(conf)# router bgp 400
DellEMC(conf-router_bgp)# bgp router-id 1.1.1.1
Following is the sample output of show ip bgp ipv4 multicast summary command.
DellEMC# show ip bgp summary
BGP router identifier 1.1.1.1, local AS number 400
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
1 neighbor(s) using 8192 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.1 200 0 0 0 0 0 00:00:00 0
DellEMC#
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Border Gateway Protocol (BGP)