Could it be the NetworkManager updates in the templatevm? I'm going to try
to figure out if/how I can try rolling those back.
If you only use one default template, then surely no.
The torvm has its own template, but everything else (including netvm and firewallvm) uses the default template.
If your can acces any network from your netVM, then your template (and
dom0) is fine.
Actually, I just discovered that my templatevms can connect to the update servers over my plain connection. (Will expand on this in another message.)
1. Try to reassign the the netvm for your AppVM first...
Ok, I tried changing some AppVM's NetVM to netvm (instead of the usual firewallvm). No change.
Also, as said above, I tried creating a new firewallvm (connected to netvm), and assigning that as the NetVM for some AppVMs, with no change.
2. check the firewall settings (if it's any)
Right, no firewall settings. (Anyway, I checked all the AppVMs, some of which have firewall settings, and some of which don't.)
3. dump your traffic on the netVM to see if AppVM traffic is going to
the right direction...
Running sudo tcpdump in the netvm, it looks like traffic is going in the right direction. But I'm not sure if I'm reading it correctly, and there are some other odd things in there that I don't understand. I attached a partial output. Would you mind taking a look? (For the output, I just started tcpdump, then tried to connect to qubes-os.org with a dispvm.)
One thing I noticed in the tcpdump output is a lot of lines like this:
06:17:44.271406 IP netvm.38028 > 10.137.2.1.domain: 7512+ A? qubes-os.org. (30)
06:17:44.271418 IP netvm.38028 > 10.137.2.1.domain: 49126+ AAAA? qubes-os.org. (30)
06:17:49.273462 IP netvm.53980 > 10.137.2.254.domain: 7512+ A? qubes-os.org. (30)
06:17:49.273509 IP netvm.53980 > 10.137.2.254.domain: 49126+ AAAA? qubes-os.org. (30)
Doesn't the "AAAA" stuff have to do with IPv6? I'm pretty sure my equipment only handles IPv4, but I'm not sure if this is normal.
(Attachment tcpdump.txt is missing)