DNS Resolution when connecting to cloud

When B5 radios (2.8.1.2) are connecting to the cloud, they appear to use Google DNS servers rather than those configured in the TCP stack.

Interesting, I think I know what’s happening here.

My configuration: B5c Radios running 2.8.0.2, they can do DNS look ups to my DNS servers, but cannot reach anything besides my management network.

So when I do a cloud connectivity test on my B5c radios I see them using my configured DNS servers (internal to my network) then when that portion of the connectivity check fails (because I don’t let my backhaul radios have access to the internet and vice versa) it checks with the secondary DNS server then finally will check with 8.8.8.8.

My best guess is that Mimosa is trying to check for a DNS configuration error/failure by attempting to reach out to Google’s DNS server. I have not done a packet capture to see what is in the DNS lookup to Google, but it is pretty small at 60 bytes.

My recommendation would be to look up Mimosa’s new MMP management tool and setup your radios so they can’t reach anything outside of your management network (and vice versa).