Fanvil phones making excess DNS number of queries

[randybell]

I just updated an on-premise v18 pbx to v20. I implemented internal DNS and notice this issue right away. I have 37 desk phones (4 fanvil, 33 Snoms)

The fanvil phones are making 1000's of DNS requests per phone, more than the PBX, and the Snom phones have made 4-10 queries each.

Anyone notice this behavious before?

in the screenshot the yellow are the fanvil phones, the blue is the pbx, red are snoms

 

[SteveITS]

Wild guess but do they use DNS blocking or restrict outbound traffic? I’ve run across IoT devices that repeatedly query DNS if they can’t connect to something.

 

[Guillaume Bourgeois]

Anyone notice this behavious before?

A Wireshark capture of your network would provide more clarity.
Several factors could explain this.
Perhaps Fanvil has suggestions for further investigation.

Regardless, Fanvil offers excellent support, so feel free to contact them directly.

What is the model and firmware version of the Fanvil phones ?


I draw @Fanvil Technical Support's attention here.

 

[Fanvil Technical Support]

Yes, providing the files or information mentioned by Guillaume would be very helpful for me to analyze this phenomenon.

I have tried deploying the V65 on hand to 3CX locally, performed an upgrade and restart, and captured packets during this process. I attempted to filter for DNS and only observed 4 Standard queries from the device, without reproducing the issue. If you could describe the steps to reproduce the problem, I could try again according to your description.


Additionally, the phenomenon of thousands of DNS queries is only on the signaling level, which is quite strange. I would like to understand what macroscopic issues have been specifically caused by the large number of DNS queries? For example, device lag, crashes, delays, etc.?