Meraki & Black Magic.

[ITGui]

I recently acquired a Blackmagic Web Presenter 4K and have been experiencing an issue where it fails to stream to YouTube when connected through a Meraki network. The Web Presenter shows “On Air”, but no data reaches YouTube. However, it streams successfully to Twitch and Vimeo. If I switch to a direct internet connection (bypassing Meraki), it works fine. This suggests Meraki is blocking or interfering with Web Presenter’s RTMP/RTMPS traffic to YouTube. I thought this was a device fluke, but we purchased 4, have only unboxed 2, they both do the same thing.

What I Have Tried So Far

Checked Meraki Event Logs: No obvious blocks on a.rtmp.youtube.com or b.rtmp.youtube.com. No firewall rules explicitly blocking Web Presenter’s IP, set Web Presenter to White List in Meraki. 

Tested With Different RTMP URLs:

rtmp://a.rtmp.youtube.com/live2 → Failed

rtmp://b.rtmp.youtube.com/live2 → Failed

rtmps://a.rtmps.youtube.com/live2 → Failed

rtmps://b.rtmps.youtube.com/live2 → Failed

Verified with OBS Studio: Using the same stream key & RTMP URL, OBS streams fine to YouTube, confirming that the problem is specific to Web Presenter’s connection through Meraki.

I appreciate any help. 

[PhilipDAth]

First of all - nice gear!

I would go to Network-Wide/Clients, find the device, and click on it.  Then look at the Policy section.  Is anything applied to this device:

Are you running a current stable firmware of better?

Failing that, you'l need to isolate which system is causing the issue.

Try temporarily turning off AMP and IPS under Threat Protection.

Failing that, check (or try temporarily removing) your content filtering rules.

[RaphaelL]

Great tips by Phil. 

Also what I like to do in that kind of troubleshooting : 

1- Take a packet capture on both LAN side of the MX and Internet1-2

2- Open Wireshark and look for DNS queries about *.youtube.com (  dns.qry.name contains "youtube.com"

3- Note the IP adresses returned to the DNS queries that interests you ( probably rmtp and rmtps.youtube.com as mentionned ) 

4- Follow these IPs ( ip.addr == X.X.X.X ) 

5- Do you see packets in both direction and pcaps? If the answer is no , something is blocking the responses. Either Content filtering , L3/L7 rules and so on.

[ITGui]

Hello! Thank you for your reply. 

I have the device whitelisted, 

Current firmware the MX250 is MX 18.211.2, on the Black Magic is 3.7 which is the latest.

Disabled the  AMP and IPS, same results.

Content Filter shows that the:


This has me stumped. 

[PhilipDAth]

>Current firmware the MX250 is MX 18.211.2

I think we are up to something like 18.211.5.  I would try doing an upgrade in case this is an already fixed bug.

[ITGui]

Thanks! That will be my next test!

[ITGui]

We tried it on a test network, same result with the latest firmware. UGH!