How to Setup Private DNS With Bind9 Chroot on CentOS 6.2 VPS

Assumed that you already buy two Virtual Private Server (VPS) but you dont want to point your nameservers on your hosting provider. To look more professional and stylish, you can run and have two private nameservers such as ns1.ehowstuff.local and ns2.ehowstuff.local. This post will show you the steps on how to setup and run your own Bind9 Chroot private nameservers on CentOS 6.2 VPS or dedicated server with atleast 2 IP addresses. To fit you requirement, please replace domain (ehowstuff.local) and ip addresses to your own domain and IPs.

ns1.ehowstuff.local : 192.168.1.44 (Master Private DNS server)
ns2.ehowstuff.local : 192.168.1.54 (Slave Private DNS server)

1. Install Bind Chroot DNS Server on both Primary and Slave server :

Master DNS Server

[root@ns1 ~]# yum install bind-chroot -y

Slave DNS server

[root@ns2 ~]# yum install bind-chroot -y

Master DNS Server

2. Login to Primary DNS server (ns1), and create a file /var/named/chroot/var/named/ehowstuff.local with the following configuration:

[root@ns1 ~]# vim /var/named/chroot/var/named/ehowstuff.local

;
;       Addresses and other host information.
;
$TTL 14400
ehowstuff.local.        IN      SOA     ns1.ehowstuff.local.    admin.ehowstuff.local. (
                                        2012060201      ; Serial
                                        86400      ; Refresh
                                        7200       ; Retry
                                        3600000    ; Expire
                                        86400 )  ; Minimum

;A record for domain mapping domain to IP
ehowstuff.local.        IN      A       192.168.1.44

;Define the atleast 2 private nameservers
ehowstuff.local.        IN      NS      ns1.ehowstuff.local.
ehowstuff.local.        IN      NS      ns2.ehowstuff.local.

; Map 2 private nameservers to IP addressess using A record
ns1     IN      A       192.168.1.44
ns2     IN      A       192.168.1.54

; Specify subdomains if any using CNAME or alias.
www     IN      CNAME   ehowstuff.local.
ftp     IN      CNAME   ehowstuff.local.

; Mail exhanger and map it IP using A record.
ehowstuff.local.        IN      MX      10      mail.ehowstuff.local.

3. Still on ns1, please generate an RNDC key :
The rndc tool is used to managed the named daemon. We need to generate a keyfile called /etc/rndc.key which is referenced both by /etc/rndc.conf and /etc/named.conf To do this we use the following command;

[root@ns1 ~]# rndc-confgen -a -c /etc/rndc.key
wrote key file "/etc/rndc.key"

View the content of the RNDC key :

[root@ns1 ~]# cat /etc/rndc.key
key "rndc-key" {
        algorithm hmac-md5;
        secret "T6tduqyMQ/YbIDXOmE0Fzg==";
};

4. on ns1, edit the /var/named/chroot/etc/named.conf file for ehowstuff.local

[root@ns1 ~]# vi /var/named/chroot/etc/named.conf

options {
       directory "/var/named";
       dump-file "/var/named/data/cache_dump.db";
       statistics-file "/var/named/data/named_stats.txt";
forwarders { 8.8.8.8; };
};
include "/etc/rndc.key";
// We are the master server for ehowstuff.local

zone "ehowstuff.local" {
        type master;
        file "/var/named/ehowstuff.local";
        allow-transfer {192.168.1.54;};
        allow-update {none;};
};

5. Start the DNS service using the following command :

[root@ns1 ~]# /etc/init.d/named start
Starting named:                                            [  OK  ]

6. Make named daemon auto start during boot :

[root@ns1 ~]# chkconfig named on

Slave DNS Server

7. Making slave DNS server can be so easy. Login to the other DNS server(ns2) and open the named.conf file. You need not create any file as the slave will automatically download the master zone information through zone transfer. After sometime, you can view the zone file. :

[root@ns2 ~]# vi /var/named/chroot/etc/named.conf

zone "ehowstuff.local" {
type slave;
file "/var/named/slaves/ehowstuff.local";
masters {192.168.1.44;};
};

Note: Bind will not allow you to run master and slave on same server, even-though you have 2 IP addresses

8. Start the DNS service using the following command :

[root@ns2 ~]# /etc/init.d/named start
Starting named:                                            [  OK  ]

9. Make named daemon auto start during boot :

[root@ns2 ~]# chkconfig named on

10. Before testing, make sure your pc or server using the Bind Chroot DNS Server that has been set up :

[root@ns1 ~]# cat /etc/resolv.conf
nameserver 192.168.1.44
nameserver 192.168.1.54

[root@ns2 ~]# cat /etc/resolv.conf
nameserver 192.168.1.44
nameserver 192.168.1.54

11. Test your DNS service :

Test from Master DNS server (ns1)

[root@ns1 ~]# dig ehowstuff.local

; <<>> DiG 9.7.3-P3-RedHat-9.7.3-8.P3.el6_2.2 <<>> ehowstuff.local
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 25783
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;ehowstuff.local.               IN      A

;; ANSWER SECTION:
ehowstuff.local.        14400   IN      A       192.168.1.44

;; AUTHORITY SECTION:
ehowstuff.local.        14400   IN      NS      ns1.ehowstuff.local.
ehowstuff.local.        14400   IN      NS      ns2.ehowstuff.local.

;; ADDITIONAL SECTION:
ns1.ehowstuff.local.    14400   IN      A       192.168.1.44
ns2.ehowstuff.local.    14400   IN      A       192.168.1.54

;; Query time: 0 msec
;; SERVER: 192.168.1.44#53(192.168.1.44)
;; WHEN: Sat Jun  2 14:46:46 2012
;; MSG SIZE  rcvd: 117

[root@ns1 ~]# host -t mx ehowstuff.local

ehowstuff.local mail is handled by 10 mail.ehowstuff.local.

[root@ns1 ~]# host -t ns ehowstuff.local

ehowstuff.local name server ns2.ehowstuff.local.
ehowstuff.local name server ns1.ehowstuff.local.

Test from Slave DNS server (ns2)

[root@ns2 ~]# dig ehowstuff.local

; <<>> DiG 9.7.3-P3-RedHat-9.7.3-8.P3.el6_2.2 <<>> ehowstuff.local
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11526
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2

;; QUESTION SECTION:
;ehowstuff.local.               IN      A

;; ANSWER SECTION:
ehowstuff.local.        14400   IN      A       192.168.1.44

;; AUTHORITY SECTION:
ehowstuff.local.        14400   IN      NS      ns2.ehowstuff.local.
ehowstuff.local.        14400   IN      NS      ns1.ehowstuff.local.

;; ADDITIONAL SECTION:
ns1.ehowstuff.local.    14400   IN      A       192.168.1.44
ns2.ehowstuff.local.    14400   IN      A       192.168.1.54

;; Query time: 3 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sat Jun  2 15:26:19 2012
;; MSG SIZE  rcvd: 117

[root@ns2 ~]# host -t mx ehowstuff.local

ehowstuff.local mail is handled by 10 mail.ehowstuff.local.

[root@ns2 ~]# host -t ns ehowstuff.local

ehowstuff.local name server ns2.ehowstuff.local.
ehowstuff.local name server ns1.ehowstuff.local.