DNS Forwarder

Install a DNS forwarder on CentOS 6.3:

yum install bind

Edit /etc/named.conf:

   1 options {
   2         directory "/var/named";
   3         forwarders { 8.8.8.8; 8.8.4.4; };
   4 };
   5 
   6 zone "example.lan" in {
   7   type forward;
   8   forwarders { 192.168.3.56; };
   9 };
  10 
  11 zone "xpto.lan" in {
  12   type forward;
  13   forwarders { 10.0.3.3; };
  14 };

Run the following commands:

service named start
chkconfig named on
netstat -a -n | grep ":53" | grep LISTEN

Check records with dig

dig @8.8.8.8 www.sapo.pt

; <<>> DiG 9.9.3-P2 <<>> @8.8.8.8 www.sapo.pt
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1365
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.sapo.pt.                   IN      A

;; ANSWER SECTION:
www.sapo.pt.            221     IN      A       213.13.146.140

;; Query time: 41 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Feb 24 15:52:15 WET 2014
;; MSG SIZE  rcvd: 56

Check records with nslookup

   1 nslookup
   2 >server 8.8.8.8
   3 >set type=any
   4 >set debug
   5 >www.sapo.pt
   6 Server:         8.8.8.8
   7 Address:        8.8.8.8#53
   8 
   9 ------------
  10     QUESTIONS:
  11         www.sapo.pt, type = ANY, class = IN
  12     ANSWERS:
  13     ->  www.sapo.pt
  14         internet address = 213.13.146.140
  15         ttl = 113
  16     ->  www.sapo.pt
  17         has AAAA address 2001:8a0:2104:ff:213:13:146:140
  18         ttl = 713
  19     AUTHORITY RECORDS:
  20     ADDITIONAL RECORDS:
  21 ------------
  22 Non-authoritative answer:
  23 Name:   www.sapo.pt
  24 Address: 213.13.146.140
  25 www.sapo.pt     has AAAA address 2001:8a0:2104:ff:213:13:146:140
  26 
  27 Authoritative answers can be found from: