Home / ubuntu / Questions / 1209020
Accepted
Tomas.R
Asked: 2020-02-09 05:31:24 +0800 CST

DNS server doesn't work (18.04 LTS)

  • 772

I have set up my ubuntu 18.04 server as a cache-only forwarding DNS server:

cat named.conf.options 

options {
        directory "/var/cache/bind";

        recursion yes;
        allow-query { 0.0.0.0; 127.0.0.1;};

        forwarders {
                8.8.8.8;
                8.8.4.4;
        };  
        forward only;

        dnssec-enable yes;
        dnssec-validation yes;

        auth-nxdomain no;    # conform to RFC1035
        listen-on-v6 { any; };
};

Firewall setup on a server : 

ufw status
Status: active

To                         Action      From
--                         ------      ----
Apache                     ALLOW       Anywhere                  
Bind9                      ALLOW       Anywhere                  
22/tcp                     ALLOW       Anywhere                  
OpenSSH                    ALLOW       Anywhere                  
Apache (v6)                ALLOW       Anywhere (v6)             
Bind9 (v6)                 ALLOW       Anywhere (v6)             
22/tcp (v6)                ALLOW       Anywhere (v6)

Output of journalctl :

journalctl -u bind9 -f


Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#43049 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f810f890 90.248.149.235#43049 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f810f890 90.248.149.235#43049 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#43049 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#50650 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f810f890 90.248.149.235#50650 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f810f890 90.248.149.235#50650 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#50650 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#45883 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#45883 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#45883 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#45883 (ssl.gstatic.com): query (cache) 'ssl.gstatic.com/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#51677 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/AAAA/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#51677 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f811e020 90.248.149.235#51677 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/A/IN' denied
Feb 08 13:16:14 ns3247177 named[2707]: client @0x7f61f8101100 90.248.149.235#51677 (ssl.gstatic.com.broadband): query (cache) 'ssl.gstatic.com.broadband/AAAA/IN' denied

Setup on my home laptop (ubuntu 18.04) :

 cat /etc/resolv.conf 
 nameserver 164.132.173.129 
 #nameserver 127.0.0.53
 options edns0
 search broadband

I change between nameservers by commenting out each and trying dig and ping commands. And when I try to use the server where I installed bind9, ping command doesn't work : 

dig google.com

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> google.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 38769
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: ab489ac00252b38c3427db005e3eb469c1411fa2c18cecdf (good)
;; QUESTION SECTION:
;google.com.            IN  A

;; Query time: 16 msec
;; SERVER: 164.132.173.129#53(164.132.173.129)
;; WHEN: Sat Feb 08 13:15:21 GMT 2020
;; MSG SIZE  rcvd: 67

This is the output of ping : 

ping -c 5 google.com
ping: google.com: Name or service not known

Can anyone tell me why my DNS server doesn't work as suppose to ?

networking server dns

1 Answers

  1. Best Answer

    You are missing "90.248.149.235;" in allow-query

    and you problably also need

    allow-recursion{90.248.149.235;};

    BTW: you can use "dig google.com @164.132.173.129" without changing resolv.conf

    • 2