On 24 February 2018 at 12:36, Reco <recovery...@gmail.com> wrote: > Ok, what about this (again, run it from the malfunctioning DNS, root is > needed for the second and third command): > > dig in a debian.org @127.0.0.1 > > ss -nplu > > iptables-save >
I've attached the output of those commands also now. > > As previously mentioned each server and client has 2 network cards, one > > which provides internet access to the client or server, and the other > > provides internal services that are on the local network after the > > firewall, the DNS server shouldn't be accessible by any clients or > servers > > that are on the internet/external side of my router/firewall. > > You're talking about inbound connections, but your problem may lie with > the outbound ones. > Oh right I see. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
root@debian:~# dig in a debian.org @127.0.0.1 ; <<>> DiG 9.10.3-P4-Debian <<>> in a debian.org @127.0.0.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 22821 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;debian.org. IN A ;; Query time: 336 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Sat Feb 24 12:38:39 GMT 2018 ;; MSG SIZE rcvd: 39 root@debian:~# ss -nplu State Recv-Q Send-Q Local Address:Port Peer Address:Port UNCONN 0 0 10.0.2.20:53 *:* users:(("named",pid=1193,fd=515)) UNCONN 0 0 192.168.0.61:53 *:* users:(("named",pid=1193,fd=514)) UNCONN 0 0 127.0.0.1:53 *:* users:(("named",pid=1193,fd=513)) UNCONN 0 0 *:68 *:* users:(("dhclient",pid=456,fd=6)) UNCONN 0 0 :::53 :::* users:(("named",pid=1193,fd=512)) root@debian:~# iptables-save root@debian:~#