Update (2022-12-06): It looks like TeamViewer fixed their DNS config (before and after).
Update (2022-11-12): I tested again after Frankie in the comments noted that it works on his machine, and indeed it does for me, too, even with DNSSEC turned back on. My only explanation is that it’s an intermittent issue.
I couldn’t figure out why TeamViewer was perpetually stuck in the ‘Not ready. Please check your connection’ state, and the help article didn’t give any clues (port 5938 was already open for outbound connections).
The log files (/opt/teamviewer/logfiles/TeamViewer15_Logfile.log in Fedora) gave a hint:
The host would cycle from router1.teamviewer.com to router16.teamviewer.com, but none of them would resolve. Long story short, DNSSEC is broken for these TeamViewer domains, and the application won’t work if none of them can be reached.
Sadly, this problem was reported years ago but nothing has changed.
Workarounds
Neither of these is good! I recommend contacting TeamViewer and letting them know about this issue (particularly if you’re a paying customer).
Hard code an IP address in hosts
Adding an IP address for router1.teamviewer.com to hosts seems to make the application functional.
I just picked the first IPv4 address and added it to /etc/hosts:
These IP addresses are of course liable to change.
Disable DNSSEC
Note: DNSSEC exists for a reason – don’t disable it unless absolutely necessary.
The nuclear option is to turn off DNSSEC checks entirely, or switch to using DNS servers that don’t support it in the first place (I recommend neither).
On Fedora 36 with systemd-resolved, this means editing /etc/systemd/resolved.conf and adding DNSSEC=no under [Resolve].
Hello,
I tested it with Fedora 36 VM, but it works, see on https://ibb.co/7rxdfxz
BR,
Frankie
Just to confirm – are you using Cloudflare or Google DNS? DNS=1.1.1.1 DNSSEC=yes under [Resolve] in /etc/systemd/resolved.conf
Yes, it`s configured, also Cloudflare as DNS, also dig results looks fine
Thanks, you’re completely correct – I tested in a new Fedora 37 VM with the same settings my machine originally had (Cloudflare DNS, DNSSEC=yes) and all the router*.teamviewer.com domains resolve fine. I turned on DNSSEC again on the original Fedora 36 machine and it also works.
Looking back through my TeamViewer log file, it looks like it’s intermittent – DNS wasn’t working on 2022-08-26, 2022-09-27 and 2022-11-07 (the date of this post), but was working on some other days. No settings were changed, so I’m more confused than ever.
I will definitely test it again several times in the next 2-3 weeks. Maybe it was really just a coincidence or it was somehow fixed.
I tested it again 3 times in the meantime and it still worked, just now I saw a reply from TeamViewer in the community post you linked. Apparently TeamViewer has changed something in the DNS setup.
BR,
Frankie
Thanks for the follow-up. It does indeed look like they’ve fixed the DNS issue: before and after.