Virtual Private Routed Network Service
512
FD 100/320Gbps NT and FX NT IHub Services Guide
3HH-11985-AAAA-TQZZA Issue: 13
 
7.10.9.26 local-preference
Table 523 local-preference command
Description This command configures a BGP virtual autonomous system (AS) number.
In addition to the AS number configured for BGP in the 
configure>router>autonomous-system context, a virtual (local) AS number is 
configured.The virtual AS number is added to the as-path message before the router’s AS 
number makes the virtual AS the second AS in the as-path.
This configuration parameter can be set at three levels: global level (applies to all peers), group 
level (applies to all peers in peer-group) or neighbor level (only applies to specified peer). Thus, 
by specifying this at each neighbor level, it is possible to have a separate as-number per EBGP 
session.
When a command is entered multiple times for the same AS, the last command entered is used 
in the configuration. The private attribute can be added or removed dynamically by reissuing 
the command.
Changing the local AS at the global level in an active BGP instance causes the BGP instance 
to restart with the new local AS number. Changing the local AS at the global level in an active 
BGP instance causes BGP to re-establish the peer relationships with all peers in the group with 
the new local AS number. Changing the local AS at the neighbor level in an active BGP 
instance causes BGP to re-establish the peer relationship with the new local AS number.
This is an optional command and can be used in the following circumstance:
Provider router P is moved from AS1 to AS2. The customer router that is connected to P, 
however, is configured to belong to AS1. To avoid reconfiguring the customer router, the 
local-as value on router P can be set to AS1. Thus, router P adds AS1 to the as-path message 
for routes it advertises to the customer router.
The no form of the command used at the global level will remove any virtual AS number 
configured.
The no form of the command used at the group level reverts to the value defined at the global 
level.
The no form of the command used at the neighbor level reverts to the value defined at the 
group level.
Default no local-as
Parameters as-number — The virtual autonomous system number, expressed as a decimal integer.
Values: 1 — 65535
private — Specifies the local-as is hidden in paths learned from the peering.
Item Description
(2 of 2)
Item Description
Syntax local-preference local-preference
no local-preference
Context configure>service>vprn>bgp
configure>service>vprn>bgp>group
configure>service>vprn>bgp>group>neighbor
(1 of 2)