Reference Guide

Border Gateway Protocol IPv4 (BGPv4) | 159
Only after the peer group responds to an OPEN message sent on the subnet does its BGP state change to
ESTABLISHED. Once the peer group is ESTABLISHED, the peer group is the same as any other peer
group.
For more information on peer groups, refer to Configure Peer Groups on page 152.
Maintain existing AS numbers during an AS migration
The local-as feature smooths out the BGP network migration operation and allows you to maintain
existing ASNs during a BGP network migration.
When you complete your migration, be sure to reconfigure your routers with the new information and
disable this feature.
Disable this feature, using the
no neighbor local-as command in CONFIGURATION ROUTER BGP mode.
Command Syntax Command Mode Purpose
neighbor {IP address |
peer-group-name local-as as
number [no prepend]
CONFIG-ROUTER-
BGP
Allow external routes from this neighbor.
Format:
IP Address: A.B.C.D
Peer Group Name: 16 characters
AS-number: 0-65535 (2-Byte) or 1-4294967295
(4-Byte) or
0.1-65535.65535 (Dotted format)
No Prepend specifies that local AS values are not
prepended to announcements from the neighbor.
You must Configure Peer Groups before assigning it to an AS.
This feature is not supported on passive peer groups.