UDP ports blocked on wired connection

Question

johann24 Author

Level 1

8 points

UDP ports blocked on wired connection

Hello,

I'm experiencing Google Meet issue for a week: no audio nor video IN/OUT

After some investigations, here is what I found:

Google Meet use UDP for IN/OUT audio/video communication
When UDP ports are blocked on the firewall, it switches to TCP
Google Meet would work for me over Wifi, but not when I'm connected through cable (MacBook Pro with several USB-C Ethernet adaptators)
Google Meet would work if I block all UDP connections at the Firewall level, even over Ethernet
Google Meet works on all other computer from my home, Ethernet or wifi and UDP enabled or not (with the same router, USB-C to Ethernet adaptator etc.)

My conclusion is that, when I'm connected through Ethernet there is something blocking UDP communication at the Mac level.

I tried rebooting, deleting the network interface in the settings, I tried several Ethernet adaptators, I tried all of my 4 USB-C interface -> same result. No audio/video, so I assume no UDP

However, even if I'm not too technical, I tried the following

nc -vnzu 74.125.250.0 53

Connection to 74.125.250.0 port 53 [udp/*] succeeded!

So it seems that UDP is enabled ....

But Google Meet would still not work if I don't block UDP at firewall level, which causes other problems.

Any help ?

Thanks in advance

MacBook

Posted on Dec 25, 2020 4:52 AM

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Answer 1

johann24 Author

Level 1

8 points

Jan 14, 2021 12:01 AM in response to johann24

FYI, this solved the issue (workaround) https://support.google.com/meet/thread/88764205?hl=en&msgid=92424194

-> disabling IPv6 and put it "only on local"

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Answer 2

johann24 Author

Level 1

8 points

Jan 13, 2021 11:44 PM in response to macthornton

Hi Macthonton

I'm glad that we share the same problem, I have the exact same behavior.

My problem appeared on Dec 8 or 9th and, looking at the logs, there has been a Mac OSX upgrade that night.

I found out preferences-pre-upgrade-source.plist files in the Library and tried to restore them with no luck.

The only work around I have so fare are: working over Wifi (which is a problem to me) or turning off any UDP connection at my house firewall (which reduces performance and block some other tools)

So none is really a viable option.

I tried to read through various settings and never saw anything related to blocked UDP port on USB-C adapter.

I hope that Apple will fix this soon.

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Answer 3

karina184

Community Specialist

Dec 30, 2020 10:05 AM in response to johann24

Thanks for getting back to us, johann24,

As Google Meet is ultimately third-party, we can't speak to the exact setup that it requires. We'd recommend that you reach out through their support site for assistance: Google Meet Help

On their website, they do have some Mac audio troubleshooting as well: Troubleshoot issues with Google Meet - Google Meet Help

Take care!

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Answer 4

johann24 Author

Level 1

8 points

Dec 28, 2020 5:24 AM in response to karina184

Hi Karina,

Thanks for your help but that does not solve the issue.

I tried deactivating Mac's firewall or allowing Google Chrome in/OUT connection but that does not help.

Also, I've not been able to test or validate that any of the other UDP services used by Apple is used (no need for any RTMP or any specific services on my computer).

Johann

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Answer 5

johann24 Author

Level 1

8 points

Dec 30, 2020 10:22 AM in response to karina184

Hi Karina,

Thanks for you reply but Google told me that there is hardly anything they can do since it's working over Wifi and over 4G. They claim that this is a network setup issue, and I cannot really disagree.

FYI, I've done further testing.

I have plugged an old airport express on my router.

if I connect to Internet through the wifi on my airport, all good
if I turn off airport and cable my mac to the router, no good
interestingly, if I connect to both airport wifi and cable router, even if wifi is set-up with higher priority, no good

It's strange that, even if my connection is supposed to go through wifi, the fact of being cabled prevent it to work ...

Any further guess ?

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Answer 6

Jan 13, 2021 6:55 PM in response to karina184

Help. I am a teacher and I am working from home. Forcing me to use wifi is not the best scenario. I upgraded from Catalina to Big Sur and found that the Google Meet failed to transmit or receive audio/video in Safari and Chrome. After several rounds of testing I've concluded that the problem is related to WiFi vs ethernet (via usb-c adapter) connection. When my MacBook Air is using ONLY WiFi there are no problems in all browsers. When connected to both WiFi and ethernet, or ethernet only, I am unable to see/hear or be seen/heard in a meeting using Chrome & Safari. Firefox *will* work but the connection dies after a few minutes.

I have tried different ethernet adapters - with the same results. Every other device on my network works great. The results are the same regardless of using the built-in camera or an external USB camera. Interestingly enough, when I start a Google Meet with WiFi, plug in the ethernet, then disconnect the WiFi, the audio and video work fine. Everything worked flawlessly before upgrading to Big Sur

https://support.google.com/meet/thread/88764205?hl=en

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