[knot-resolver-users] Re: Resolving problem connectivity.samsung.com.cn even on dual-stack

What I see, the problematic IPs 27.106.204.41 and 27.106.204.42 look to be "open resolvers" with high timeout rate. I think they are misconfigured and misused what causes the overal problems. dig google.com @27.106.204.41 ; <<>> DiG 9.16.15-Debian <<>> google.com @27.106.204.41 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 35456 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;google.com. IN A ;; ANSWER SECTION: google.com. 60 IN A 93.46.8.90 ;; Query time: 188 msec ;; SERVER: 27.106.204.41#53(27.106.204.41) ;; WHEN: Mon Sep 19 14:11:38 CEST 2022 ;; MSG SIZE rcvd: 54 po 19. 9. 2022 o 13:55 Vladimír Čunát &lt;vladimir.cunat(a)nic.cz&gt; napísal(a): > > So, the log shows that it won't connect even on TCP level. TCP is tried first at this point due to cache containing information about these IPs timing out (over UDP). > > However, when I try from my network these IPs do reply, both over UDP and TCP. I'd probably look into traceroute, etc. > > --Vladimir