PBF Rule Monitoring - Forced egress i/f?

jhossbach — Sat, 20 Jan 2024 17:35:02 GMT

I have a dual ISP configuration. ethernet1/1 is primary Internet. ethernet1/2 is backup wireless Internet (phone or dedicated hot spot as needed). ethernet1/2 is connected to an old Linksys router running DD-WRT and it automatically connects to my hotspot when I turn it on. Otherwise, there is no Internet access via ethernet1/2.

I have a PBF rule configured with an egress interface of ethernet1/2, a next hop of 192.168.2.1, and a monitor configured for 8.8.4.4. Obviously 8.8.4.4 is pingable from any internal network client as it is using ethernet1/1 for Internet access. However, running show pdf rule all shows the PBF rule state as Disabled instead of Active.

The only documentation I can find on Path monitoring for PBF is: https://docs.paloaltonetworks.com/pan-os/10-2/pan-os-admin/policy/policy-based-forwarding/pbf/path-monitoring-for-pbf

It does not say that the monitor doesn't follow routing rules and instead forces out the egress interface. It also doesn't say anything about the next hop being used. I'm presuming at this point that the egress interface and/or next hop configuration on the Forwarding tab of the PBF rule play a role in how the monitor operates, but I would like to find some official documentation that can support the theory, especially if the theory is wrong and this is working by accident or some other function.

Bottom line: Why is this working?

Re: PBF Rule Monitoring - Forced egress i/f?

Raido_Rattameister — Sun, 21 Jan 2024 13:38:37 GMT

Rule state "Disabled" means that monitoring took PBF down.

To troubleshoot:

Uncheck "Disable this rule if nexthop/monitor ip is unreachable" to force PBF to be active.
Generate some traffic that matches PBF.
Go to Monitor > Traffic and check logs.
Did traffic flow work?
Did you get any replies from ethernet1/2?
Do you have source nat policy configured for traffic exiting ethernet1/2 interface?

When you get traffic working then you can re-check "Disable this rule if nexthop/monitor ip is unreachable" checkbox to enable PBF rule monitoring.

topic Re: PBF Rule Monitoring - Forced egress i/f? in Next-Generation Firewall Discussions

PBF Rule Monitoring - Forced egress i/f?

Re: PBF Rule Monitoring - Forced egress i/f?