topic not able to access certain web sites from host behind PAN firewalls in General Topics

not able to access certain web sites from host behind PAN firewalls

dtran — Tue, 19 Jan 2021 19:41:34 GMT

I am trying to access http://www.brokercheck.com from behind the PAN firewall via dynamic NAT without any success. I have other customers behind different PAN firewalls, regardless of PAN OS version, with the same issue access website http://www.brokercheck.com.

The FW rule is wide open "any any accept log"

It works for customers NOT behind PAN firewalls. In other words, hosts behind Cisco ASA and checkpoint firewalls can access http://www.brokercheck.com without any issues.

I have a TAC case opened with PaloAlto support and waiting to hear back from them.

Thoughts?

Re: not able to access certain web sites from host behind PAN firewalls

SutareMayur — Wed, 20 Jan 2021 04:17:12 GMT

Hi @dtran ,

What are you seeing under traffic logs? Traffic logs should give more clarity for this. You can also check few other points like,

1.First, check if traffic for below URL is reaching the firewall. If there are any DNS issues on the source system, you won't see any traffic on the firewall.

2. Check if the required security policy is getting applied to below URL traffic on Palo Alto and if security policy is allowing the traffic,

3. Check if any other security policy profile e.g. URL filtering is blocking it.

4. NAT Policy & desired routing is happening on the firewall while accessing below URL.

Please check these points.

Re: not able to access certain web sites from host behind PAN firewalls

dtran — Wed, 20 Jan 2021 13:34:00 GMT

No issue with DNS, URL filtering, NAT.... Did I mention that if I replace the PAN with Cisco or Checkpoint, I don't have this issue?

This issue is reproducible from multiple customers that are behind the PAN firewalls, from different locations and different ISP.

Re: not able to access certain web sites from host behind PAN firewalls

SutareMayur — Thu, 21 Jan 2021 09:35:59 GMT

Hi @dtran ,

I tested URL from my one of the test system which is behind palo alto and URL is working. It gets redirected to https://brokercheck.finra.org/

Re: not able to access certain web sites from host behind PAN firewalls

dtran — Tue, 26 Jan 2021 21:57:53 GMT

I found the solution here: https://www.networkdefenseblog.com/post/wireshark-tcp-challenge-ack

Apparently many users who are behind PAN firewalls have issues access this site.