Fail-over VPN site-to-site

[BigPalo]

Hi,

We have a PA with two VPNs configured. VPN-Main is the active one and if this vpn falls, the traffic must go through the other VPN-backup. The fact is that when the active VPN falls, the route that has the Palo Alto continues going through the previous VPN, it does not refresh the route and adds it through the new tunnel.

This configuration worked when this deployment was done but suddenly stop working.

We have configured a tunnel monitor with destination IP and profile fail-over.

In VPN Main (active):

In VPN (backup):

And this is the route table:

tunnel.29 is the main (active). The metric is 2.

tunnel.27 is the backup. Metric is 5.

Why PA is not deleting the "active" route if the monitor ip is down through the vpn down.

[OtakarKlier]

Hello,

Its because they are static routes. For this type of config I would recommend one of the following.

For VPN tunnel A

Use Policy based forwarding with the monitoring and "Disable this rule if nexthop/monitor ip is unreachable" checked.

Then use a static route for tunnel B

The PAN will enforce PBF policies prior to the routing table so when the PBF disables its self the routing table takes affect.

The second option is to use PBF for both tunnels and tunnel B lower on the list. The firewall reads these from top down so it will always prefer tunnel A unless it goes down then switch to tunnel B.

Hope that makes sense.

[BigPalo]

Yes, but its not necesary PBF. It should be work only with tunnel monitoring

https://docs.paloaltonetworks.com/pan-os/7-1/pan-os-admin/vpns/set-up-tunnel-monitoring

Whats the problem with static routes???  static route should dissapear when monitor ip is down.

[LukeBullimore]

Hi @BigPalo

The static route will be removed from the FIB not the RIB - if you go to the VR and click "More runtime stats" -> "Forwarding Table" it shouldn't be there.

[BigPalo]

but the new traffic should use backup tunel, since the static route dissapear for active path.