- proxy in standard mode
- webfilter log shows 504 errors with timeouts while trying to reach ping3.teamviewer.com
- tcpdump on client shows the the connection gets interrupted and tries to retransmit the initial packet several times
- firewall log shows blocked packages from client to teamviewer server (I assume the retransmit packages get blocked because they do not pass thru the webfilter but over 443)
Do you have an FQDN in 'Address' and *.teamviewer.com in 'Exceptions'? If you do that, your browser should skip the Proxy in Standard mode. The 'Transparent Mode Skiplist' does not apply in Standard Mode.
Tools like TeamViewer need a session from the desktop device. The whole purpose of Standard Mode is to create the session from the UTM device. So the technologies are fundamentally incompatible. You need to exclude teamviewer.com from your proxy script rather than at the UTM level.
A few days ago it suddenly started working again. Probably wasn't an issue caused by the firewall. Probably a couple of problems between our government net and some teamviewer servers. This answer of Bob probably would fit best as answer if it have not been a problem caused by "external" issues.
I have installed Teamviewer QS in our Citrix envoritment. I launch it, then i can see id and password. If i try to connect to Virtual Desktop through teamviewer from a local client, it try very fast and then close connection. I do not get any help in the event viewer on server/local client.
I was wondering if TeamViewer uses certificate pinning so I tried to decrypt it. I've set a simple decrypt rule to decrypt everything from one IP going to internet. But the rule doesn't seem to work for TeamViewer. All SSL sessions are decrypted but teamviewer-base isn't. I've also tried sharing file over it and I didn't see it in data log, also application didn't change to teamviewer-sharing. So I'm pretty sure TeamViewer didn't get decrypted while other SSL sessions did.
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