Removing Private As Numbers From Updates - Juniper BGP - CONFIGURATION GUIDE V 11.1.X Configuration Manual

JUNOSe 11.1.x BGP and MPLS Configuration Guide
neighbor maximum-prefix

Removing Private AS Numbers from Updates

You might choose to conserve AS numbers by assigning private AS numbers to some
customers. You can assign private AS numbers from the range 64,512 to 65,535.
However, when BGP advertises prefixes to other ISPs, it is undesirable to include the
private AS numbers in the path. Configure the external neighbors to drop the numbers
with the neighbor remove-private-as command.
neighbor remove-private-as
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Configuring BGP Peer Groups
host1(config)#router bgp 100
host1(config-router)#neighbor 2.2.2.2 maximum-prefix 1000
Use to control how many prefixes can be received from a neighbor.
If you specify a BGP peer group by using the peerGroupName argument, all the
members of the peer group inherit the characteristic configured with this
command unless it is overridden for a specific peer.
By default, BGP checks the maximum prefix limit only against accepted routes.
You can specify the strict keyword to force BGP to check the maximum prefix
against all received routes. The accepted and received routes will likely differ
when you have configured inbound soft reconfiguration and route filters for
incoming traffic.
This command takes effect immediately. To prevent a peer from continually
flapping, when it goes to state idle because the maximum number of prefixes
has been reached, the peer stays in state idle until you use the clear ip bgp
command to issue a hard clear.
Use the no version to remove the maximum number of prefixes.
See neighbor maximum-prefix
Use to remove private AS numbers only in updates sent to external peers.
All private AS numbers are removed regardless of their position in the AS-path
attribute and regardless of the presence of public AS numbers.
If you specify a BGP peer group by using the peerGroupName argument, all the
members of the peer group inherit the characteristic configured with this
command. You cannot override the characteristic for a specific member of the
peer group.
Example
host1(config-router)#neighbor 10.10.128.52 remove-private-as
New policy values are applied to all routes that are sent (outbound policy) or
received (inbound policy) after you issue the command.
To apply the new policy to routes that are already present in the BGP routing
table, you must use the clear ip bgp command to perform a soft clear or hard
clear of the current BGP session.