• DNSForwarder

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== nslookup >server 8.8.8.8 >set type=any >set debug >www.sapo.pt Server: 8.8.8.8 Address: 8.8.8.8#53

• QUESTIONS:
  • www.sapo.pt, type = ANY, class = IN
  ANSWERS:

  -> www.sapo.pt

  • internet address = 213.13.146.140 ttl = 113

  -> www.sapo.pt

  • has AAAA address 2001:8a0:2104:ff:213:13:146:140 ttl = 713
  AUTHORITY RECORDS: ADDITIONAL RECORDS:

Non-authoritative answer: Name: www.sapo.pt Address: 213.13.146.140 www.sapo.pt has AAAA address 2001:8a0:2104:ff:213:13:146:140

Authoritative answers can be found from: }}}