Sharing Screen Through Webex Not Workin With Palo Alto Firewall

[amb1s1]

I would like to know if any of you have my setup:

Palo Alto Firewall Doing Dynamic Nat(PAT) Translating to one IP

Cisco SX20 Telepresence

So we are having some issues since we move to our new office. The problem is this; we have a webex meeting, everybody joins in also a telepresence on a room. When a person shares the screen, everybody sees the screen sharing on all laptop and home, but not on the SX20 telepresence. I was with both Cisco and Palo Alto engineer and today was our second day without coming out with a solution. Also what it is weird is that sometimes work and sometimes won't. I would see if anybody have this same issue with their Palo Alto and how do you fixed it? Thanks

[Rishabh Gupta]

HI David,

So here the issue is : intermittent incoming presentation on SX20 during WebEx calls, after relocation.

It seems to be a network / firewall issue .

Please have a look at the following link to make sure all ports and IP address are opened to Allow WebEx Traffic in your network :

https://cisco-support.webex.com/guest/articles/en_US/Usability_FAQs/WBX264/myr=false

You can also perform below test to confirm more on the issue :

1. Connect two video endpoints :  this SX20 and another one from a different location which works fine ( or a PC with Wireshark ) to the same WebEx meeting.

• Enable PCAP on both the participants and also on firewall just before making the call.
• First share the presentation from far end and see if this SX20  receives it. (If no, that means issue gets replicated).
• Now, try this : Share content from this SX20 and check far-end can see it. If yes,  stop sharing and immediately ask far end to share content and check if SX20 can receive ? 
• Monitor the live traffic status on firewall and relate the info with the PCAP collected to isolate the issue.

[charles huang]

I have similar issue on DX80 and SparkBoard that is registered to Spark. We use PA firewall as well.

If we disconnect the call while the content is shared, and rejoin, then content shows up.

Has anyone found if the problem is Firewall related? 

[lskinnc]

Hey Charles - Did you ever find a solution for this issue?  We're having the exact problem.  Using mostly MX800's and our Network Engineer doesn't see any blocks at the Palo Alto firewall.

Thanks

-Scott

[lskinnc]

Hey Charles - Did you ever find a solution for this issue? We're having the exact problem. Using mostly MX800's and our Network Engineer doesn't see any blocks at the Palo Alto firewall.



Thanks



-Scott

[lskinnc]

We worked with Cisco and Palo Alto support.  Turns out we were hitting the default Palo Alto UDP timeout of 30 sec, which was causing the issue when the sharing started > 30 secs after the video endpoint joined the meeting.  They had us create a separate firewall Application rule where we increased the timeout to 10800 sec, which resolved the issue.

[Neilsonw]

David, We have the same issue with RoomKit on content sharing with Palo Alto firewall.  Can you provide me both the Cisco and PAN ticket, so I can call them to refer to?  or if possible what exactly you have to do on the PAN to make it work?