VOIP / Go-Box-100 issue with NextDNS ( stun.t-online.de)
I am running a Gigabit Go-Box-100 for VOIP communication.
This was working for months until I discovered a failed connection today.
Only changing the DNS servers from NextDNS to public DNS (Google & Cloudflare) fixed it finally.
No blocked lookups of servers appeared in the NextDNS protocol, so I really don't know why the connection is no longer working when I use NextDNS.
Exactly, I did it the same way. I found out, that it is the EDNS-client (enabled) subnet setting, that cripples the DNS request for the VOIP services. If you want, you can use a different configuration on NextDNS, and link the IPv4 of your DSL to it, and use the IPv4 servers from the config page in your Fritzbox. But anyway, I do not think, that it's worth the hustle.... Just take official DNS server for your VOIP services, there are no malicious or advertisment calls from it anyway....