How to configure BGP ASN stripping in Advanced Routing Engine

• Palo Alto firewall running 10.2 or later
• Panorama running 10.2 or later

• It is sometimes needed to strip/remove BGP ASNs from the prefix's attributes. This is usually done while advertising a prefix towards the Internet or for privacy compliances reasons.
• This article describes the process to do this in Advanced Routing Engine.

• Basically, we need to add the BGP ASN number which we want to strip/remove in the ASPATH Exclude option in the route-map which is applied to the BGP Neighbour.
• Below are the screenshots detailing the before and after change in attribute as seen on the neighbouring device.

Before the option is used: (When no ASN is mentioned in the ASPATH Exclude option).

How the prefix was seen on the neighbour (Notice the ASN 1 seen):

Below is how to add the BGP ASN to the ASPATH Exclude option:

Note that when the prefix is seen on the neighbour, the BGP ASN 1 is not seen in the BGP ASNs.

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