Ruby

I need to get TXT records for domain qmc.kz . As far as I understand the nameservers for the domain are ns1.hoster.kz. , ns2.hoster.kz. and ns3.hoster.kz.:

$ dig ns qmc.kz ; <<>> DiG 9.11.3-1ubuntu1.15-Ubuntu <<>> ns qmc.kz ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51732 ;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 65494 ;; QUESTION SECTION: ;qmc.kz. IN NS ;; ANSWER SECTION: qmc.kz. 3600 IN NS ns2.hoster.kz. qmc.kz. 3600 IN NS ns3.hoster.kz. qmc.kz. 3600 IN NS ns1.hoster.kz. ;; Query time: 240 msec ;; SERVER: 127.0.0.53#53(127.0.0.53) ;; WHEN: Thu Sep 09 12:59:58 +07 2021 ;; MSG SIZE rcvd: 96 

I can get required records using dig:

$ dig txt qmc.kz @ns1.hoster.kz. ; <<>> DiG 9.11.3-1ubuntu1.15-Ubuntu <<>> txt qmc.kz @ns1.hoster.kz. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49918 ;; flags: qr aa rd; QUERY: 1, ANSWER: 5, AUTHORITY: 3, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ; COOKIE: 5381a01e42eb0faf010000006139a37b909696e4de36b1b8 (good) ;; QUESTION SECTION: ;qmc.kz. IN TXT ;; ANSWER SECTION: qmc.kz. 3600 IN TXT "mailru-verification: 811c66f7dca24bbe" qmc.kz. 3600 IN TXT "google-site-verification=ag5aCNvglCNQ7VZyskRRxicBgdhcYsTECJLtEll41Rk" qmc.kz. 3600 IN TXT "v=DKIM1;k=rsa;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDv9m815JDZENyfbWhxGazaezQ8jn4nCc1Z6eMJ/WXXbHz1wiYDpu6E6KG1huVZZxJ1pT3hzZa1Phe0tWGPDUyHN4prxGwxCTVBLn0R6aSum9ZIvgyeBAod8ZVr4i9euoouBdqUQ3iuinVYRCj1OOj4PQ6ttJ9Hr0ZxyYqHotv9hQIDAQAB" qmc.kz. 3600 IN TXT "update_dns_zone" qmc.kz. 3600 IN TXT "v=spf1 redirect=_spf.yandex.net" ;; AUTHORITY SECTION: qmc.kz. 3600 IN NS ns2.hoster.kz. qmc.kz. 3600 IN NS ns3.hoster.kz. qmc.kz. 3600 IN NS ns1.hoster.kz. ;; Query time: 123 msec ;; SERVER: 185.116.195.38#53(185.116.195.38) ;; WHEN: Thu Sep 09 13:02:35 +07 2021 ;; MSG SIZE rcvd: 574 

Here is how I try to get the same records in ruby:

require 'resolv' Resolv::DNS.new(nameserver: 'ns1.hoster.kz.').getresources('qmc.kz', Resolv::DNS::Resource::IN::TXT) 

and it produces the following error:

/usr/local/lib/ruby/3.0.0/resolv.rb:892:in `initialize': Connection refused - connect(2) for "ns1.hoster.kz." port 53 (Errno::ECONNREFUSED) from /usr/local/lib/ruby/3.0.0/resolv.rb:892:in `new' from /usr/local/lib/ruby/3.0.0/resolv.rb:892:in `initialize' from /usr/local/lib/ruby/3.0.0/resolv.rb:569:in `new' from /usr/local/lib/ruby/3.0.0/resolv.rb:569:in `make_tcp_requester' from /usr/local/lib/ruby/3.0.0/resolv.rb:537:in `block in fetch_resource' from /usr/local/lib/ruby/3.0.0/resolv.rb:1125:in `block (3 levels) in resolv' from /usr/local/lib/ruby/3.0.0/resolv.rb:1123:in `each' from /usr/local/lib/ruby/3.0.0/resolv.rb:1123:in `block (2 levels) in resolv' from /usr/local/lib/ruby/3.0.0/resolv.rb:1122:in `each' from /usr/local/lib/ruby/3.0.0/resolv.rb:1122:in `block in resolv' from /usr/local/lib/ruby/3.0.0/resolv.rb:1120:in `each' from /usr/local/lib/ruby/3.0.0/resolv.rb:1120:in `resolv' from /usr/local/lib/ruby/3.0.0/resolv.rb:521:in `fetch_resource' from /usr/local/lib/ruby/3.0.0/resolv.rb:507:in `each_resource' from /usr/local/lib/ruby/3.0.0/resolv.rb:498:in `getresources' from (irb):6:in `<main>' ... 3 levels... 

The same error if I try using the IP address of the nameserver (just in case ns1.hoster.kz. points to 185.116.195.38).

After some research of resolv.rb I figured out that the requests to nameservers could be UDP (by default) or TCP.

I also tried TCP request with dig:

$ dig +tcp txt qmc.kz @ns1.hoster.kz. ;; Connection to 185.116.195.38#53(185.116.195.38) for qmc.kz failed: connection refused. 

But I can get the same records using TCP for example from Google's or Cloudflare's DNS servers:

dig +tcp txt qmc.kz @1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.15-Ubuntu <<>> +tcp txt qmc.kz @1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11124 ;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ;; QUESTION SECTION: ;qmc.kz. IN TXT ;; ANSWER SECTION: qmc.kz. 3600 IN TXT "update_dns_zone" qmc.kz. 3600 IN TXT "v=spf1 redirect=_spf.yandex.net" qmc.kz. 3600 IN TXT "mailru-verification: 811c66f7dca24bbe" qmc.kz. 3600 IN TXT "google-site-verification=ag5aCNvglCNQ7VZyskRRxicBgdhcYsTECJLtEll41Rk" qmc.kz. 3600 IN TXT "v=DKIM1;k=rsa;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDv9m815JDZENyfbWhxGazaezQ8jn4nCc1Z6eMJ/WXXbHz1wiYDpu6E6KG1huVZZxJ1pT3hzZa1Phe0tWGPDUyHN4prxGwxCTVBLn0R6aSum9ZIvgyeBAod8ZVr4i9euoouBdqUQ3iuinVYRCj1OOj4PQ6ttJ9Hr0ZxyYqHotv9hQIDAQAB" ;; Query time: 192 msec ;; SERVER: 1.1.1.1#53(1.1.1.1) ;; WHEN: Thu Sep 09 13:14:30 +07 2021 ;; MSG SIZE rcvd: 483 

And the last point I can get these record in Ruby also using Cloudflare's DNS:

Resolv::DNS.new(nameserver: '1.1.1.1').getresources('qmc.kz', Resolv::DNS::Resource::IN::TXT) 

gives

[#<Resolv::DNS::Resource::IN::TXT:0x000055cf55865db0 @strings=["google-site-verification=ag5aCNvglCNQ7VZyskRRxicBgdhcYsTECJLtEll41Rk"], @ttl=3600>, #<Resolv::DNS::Resource::IN::TXT:0x000055cf55865720 @strings= ["v=DKIM1;k=rsa;p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDv9m815JDZENyfbWhxGazaezQ8jn4nCc1Z6eMJ/WXXbHz1wiYDpu6E6KG1huVZZxJ1pT3hzZa1Phe0tWGPDUyHN4prxGwxCTVBLn0R6aSum9ZIvgyeBAod8ZVr4i9euoouBdqUQ3iuinVYRCj1OOj4PQ6ttJ9Hr0ZxyYqHotv9hQIDAQAB"], @ttl=3600>, #<Resolv::DNS::Resource::IN::TXT:0x000055cf55865180 @strings=["update_dns_zone"], @ttl=3600>, #<Resolv::DNS::Resource::IN::TXT:0x000055cf558642d0 @strings=["v=spf1 redirect=_spf.yandex.net"], @ttl=3600>, #<Resolv::DNS::Resource::IN::TXT:0x000055cf5585b130 @strings=["mailru-verification: 811c66f7dca24bbe"], @ttl=3600>] 

Do I miss something? Is there issues at nameserver or should Ruby handle this case somehow?