Short-term outages with DoT
I have set up the "DNS-over-TLS/QUIC" address in my Android smartphone as "private DNS" and also in the router for the home network. Basically, the service works very well, but several times a day I have short-term outages of up to 30 seconds on all end devices, both at home and mobile, during which no address can be resolved.
The problem apparently only occurs with the natively supported protocol DoT. If I only enter the unencrypted IPv6 DNS server in the router, I cannot determine any comparable failures so far.
I do have the exact same issue when using DoT on my router (which is a fritzbox). However I found 6 month old threads here from users reporting the same issue with different brands - and other users with a fritzbox also.
Unfortunately it seems that this issue was not resolved by now. I am not very happy about that :(
The problem also exists via smartphone in the mobile network - so I can rule out the router as the sole source of the error.
As a temporary measure, I now use the DoH entry on the systems that natively support it (Chrome, Windows 11). This way, uninterrupted web browsing is at least possible. However, I do not consider this setup ideal. I do not want to install additional apps and they are not available everywhere (e.g. router).
I have a Netgate pfSense router experiencing the same issues with DoT configs except my outages are for longer periods of times, sometimes up to 10 minutes.
Not only is my router unable to resolve addresses, the two iphones I have in the house directed to NextDNS DoT DNS servers were not resolving.
After complaints from family members about TVs, laptops, etc not working i had to divert to the plain-text configs.
Also, this isn’t a new issue. It appears often and it’s quite annoying.
That last time this happened it was an issue with Stubby not gracefully handling slow handshakes with NextDNS, which was supposed to be fixed, but I do know there was an issue filed on the Stubby GitHub regarding this as well.
TLS Connection Failures - Stubby - Bug Reports - NextDNS Help Center
I have now tested personal AdGuard DNS beta intensively for two days. No timeouts via DoT so far, neither natively via my Android smartphone nor via my router. Also, the name resolution seems a little bit faster to me, but may just be imagination.
The range of functions of AdGuard DNS is still quite limited. The interface is also not as innovative and clear as NextDNS. Yet!
So @NextDNS, use your advantage over the upcoming competition and finally fix the problems with DoT! :-) I would like to stay here as paying customer.
Using AdGuardHome and forwarding upstream to the dot://url or doh://url and then checking the hit counter in NextDNS Analytics.. I found that doh was (almost) 3x used than dot.
Unbound and Core can use dot as a recursive forward.. and dnscrypt-proxy can only do doh
I've used clash (proxy) which can support dot doh directly.. but I have way to prove how it's goes from one to the other.. I was also trying to name the nextdns-cli to see how that appears in the logs.. but it seems to just come from the ip address of the wan connection it is coming from..
I can't seem to name that endpoint like you can with dot://dot-custom-name-123abc.dns.nextdns.io or doh://dns.nextdns.io/123abc/doh-custom-name
I'm not sure if AdGuardHome had problems with dot and that is why the count was uneven..
I just started encountering issues today with DoH failing only for v4, v6 is still resolving fine and I see it in my NextDNS logs, yet I am getting no return on v4 addresses, I needed to fallback to Cloudflare for v4 but have continued testing with the NextDNS DoH v4 issues.
Were any changes made today? Or could this be my ISP doing some form of DPI that is messing with my encrypted DNS?