topic Re: BGP backdoor in General Topics

BGP backdoor

GnContente — Sat, 29 Jan 2022 17:58:24 GMT

Hi All,

In my setup, i have the use case where i need to prefer an IGP over eBGP route. One of my objectives is to try not to change BGP AD. In Cisco routers there is a feature known as BGP backdoor which allows you to prefer an IGP route over eBGP route.

How can i make an IGP route preferable over an eBGP learned route? Can this be done on PA without changing the BGP AD?

TIA

Re: BGP backdoor

PavelK — Sat, 05 Feb 2022 22:51:23 GMT

Thank you for the post @GnContente

In Cisco terms, the BGP backdoor is changing administrative distance of specified prefix to 200. In Palo Alto Firewall, regardless it is using virtual router or advanced routing engine, I do not see such option except of changing administrative distance globally for whole BGP process, so I believe the answer is no. There is unfortunately no option that would be an equivalent of BGP backdoor.

If you prefer not to change administrative distance, perhaps you can set BGP aggregation on the router you are peering with to larger prefix, then your IGP learned route will win based on shortest match.

Kind Regards

Pavel

Re: BGP backdoor

PavelK — Wed, 02 Mar 2022 06:12:57 GMT

@GnContente I would like to follow up with this topic.

The BGP Backdoor has been introduced in PAN-OS 10.2 that was just released: https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-release-notes/features-introduced-in-pan-os/networking-features.html

Kind Regards

Pavel Kucera