If you use the same DNS server, it seems they are spending time validating your permission to use the server. Either way, they somehow quickly let me know that I shouldn't bother trying to get DNS results from them. Or maybe they just quickly closed/declined the UDP port 53 connection. For me, who is in WA State of USA, halfway around the world from this DNS server's location that is presumably in the Netherlands, I find that they did set up a DNS server that receives my traffic, and they validated whether I was authorized to use them, and they figured out that I wasn't, and they bothered to send a reply (using the DNS protocol) which let me know that they refused my query. This is different than asking them about. However, in this case, you are not asking them about, but you are asking them about. I'm saying I distrust the results.)ДЇirst, just to get this out of the way, your current question shows: (I'm not saying that you are inaccurately reporting the results. When trying the same call from two of my servers (both running linux) I get the correct answer (127.0.0.1) both when specifying and when not specifying the nameserver.Дoes this point to a buggy router or could there be something else that is going on?ДЄctually, I sadly distrust some of the results you provided. (At work, adding the nameserver causes problems, but I assume that is because of a firewall and unrelated to the issues at home.) When I add the nameserver explicitly while running nslookup at home, it works without any problems: $ nslookup However, from home I'm not getting any response: $ nslookup I can use nslookup to find this from work without any problems: $ nslookup I have set up a subdomain with an A record of 127.0.0.1 (set up more than 24 hours ago at the authoritative server, just like how I would set up a normal subdomain) for the sake of development.

Dsldevice domain not trusted