Palo Alto BGP routes from Azure

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Palo Alto BGP routes from Azure

L3 Networker

Palo 5220 running at the edge, using VPN tunnel to Azure virtual WAN running eBGP. Palo iBGP peered to switches, switches peered eBGP to Azure Express Route. My issue is VPN route is always installed in route table rather than express route, I assume because eBGP is AD 20 vs iBGP AD 200. I have tried local pref and weight on the palo to try and force it to install iBGP route coming from Express route with no luck. Any one else have a similar issue?

 

1 accepted solution

Accepted Solutions

Hi @S_Williams901 ,

During route lookup administrative distance is always first to check, so no matter what MED, local pref or weight you set eBGP will always be preferable. AD is used to select route learned from different routing protocols, while the BGP metrics will be used when multiple routes from same routing protocol were learned.

 

Obviously the quick and dirty fix is to increase (or decrease) administrative distance metric for either iBGP or eBGP. However  you need to double check how this will effect any other routing in your environment, since this change is per virtual-router and will affect all routes

 

Have you considered the option to use eBGP between firewall and switches? You could assign dedicate private AS number to the firewall, which is different from the AS of the switches. This way you could play with BGP metrics and tell FW to use express route when available.

View solution in original post

1 REPLY 1

Hi @S_Williams901 ,

During route lookup administrative distance is always first to check, so no matter what MED, local pref or weight you set eBGP will always be preferable. AD is used to select route learned from different routing protocols, while the BGP metrics will be used when multiple routes from same routing protocol were learned.

 

Obviously the quick and dirty fix is to increase (or decrease) administrative distance metric for either iBGP or eBGP. However  you need to double check how this will effect any other routing in your environment, since this change is per virtual-router and will affect all routes

 

Have you considered the option to use eBGP between firewall and switches? You could assign dedicate private AS number to the firewall, which is different from the AS of the switches. This way you could play with BGP metrics and tell FW to use express route when available.

  • 1 accepted solution
  • 2025 Views
  • 1 replies
  • 0 Likes
  • 101 Subscriptions
Like what you see?

Show your appreciation!

Click Like if a post is helpful to you or if you just want to show your support.

Click Accept as Solution to acknowledge that the answer to your question has been provided.

The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!

These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!

The LIVEcommunity thanks you for your participation!