Configuring DNS server on linux for 11gr2 SCAN name

1) Disable firewall
service iptables stop
service ip6tables stop

2) Install following rpms
bind-libs
bind
bind-utils

2) edit /etc/named.conf file (Make sure that dns name server name and scan name is different and scan ips are not being already used)

[root@linuxdns named]# cat /etc/named.conf
//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//

options {
        listen-on port 53 { 127.0.0.1; 10.10.20.6; };
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        #allow-query     { localhost; };
        allow-query     { any; };
        query-source port 53;
        query-source-v6 port 53;
        recursion yes;

        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside auto;

        /* Path to ISC DLV key */
        bindkeys-file "/etc/named.iscdlv.key";
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

zone "." IN {
        type hint;
        file "named.ca";
};

zone "kmccorp.com" IN {
        type master;
        file "kmccorp.com.zone";
        allow-update { none; };
};

zone "20.10.10.in-addr.arpa." IN {
        type master;
        file "20.10.10.in-addr.arpa";
        allow-update { none; };
};

include "/etc/named.rfc1912.zones";

[root@linuxdns named]#

3)
In the zone definitions we defined the file containing the zone configuration. These files are located in the "/var/named/" directory.
For a RAC installation create/edit the file associated with your zone its look like bellow (/var/named/kmccorp.zone )

[root@linuxdns named]# pwd
/var/named
[root@linuxdns named]# cat kmccorp.com.zone
$TTL    86400
@               IN SOA  localhost root.localhost (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum
                IN NS           localhost
localhost       IN A            127.0.0.1
linuxrac        IN A    10.10.20.1
linuxrac-priv   IN A    192.168.70.1
linuxrac-vip    IN A    10.10.20.3
linuxdns-scan   IN A    10.10.20.10
linuxdns-scan   IN A    10.10.20.11
linuxdns-scan   IN A    10.10.20.12
[root@linuxdns named]#

4) Next I need to create the "/var/named/20.10.10.in-addr.arpa" file for my public network reverse lookups.
This file has the following contents, where "linuxdns.kmccorp.com" is the name of the DNS server

[root@linuxdns named]# cat 20.10.10.in-addr.arpa
$ORIGIN 20.10.10.in-addr.arpa.
$TTL 1H
@       IN      SOA     linuxdns.kmccorp.com.     root.linuxdns.kmccorp.com. (      2
                                                3H
                                                1H
                                                1W
                                                1H )
20.10.10.in-addr.arpa.         IN NS      linuxdns.kmccorp.com.

1     IN PTR  linuxrac.kmccorp.com
3     IN PTR  linuxrac-vip.kmccorp.com
10    IN PTR  linuxdns-scan.kmccorp.com
11    IN PTR  linuxdns-scan.kmccorp.com
12    IN PTR  linuxdns-scan.kmccorp.com

[root@linuxdns named]#
[root@linuxdns named]#
[root@linuxdns named]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

10.10.20.6 linuxdns.kmccorp.com linuxdns
[root@linuxdns named]#

5) Start the dns service
[root@linuxdns named]#service named start
checkconfig named on

6) On the client side include following content in file /etc/resolv.conf

nameserver 10.10.20.6
search kmccorp.com

7) Test it

# nslookup linuxdns-scan.kmccorp.com
Server:         10.10.20.6
Address:        10.10.20.6#53

Name:   linuxdns-scan.kmccorp.com
Address: 10.10.20.10
Name:   linuxdns-scan.kmccorp.com
Address: 10.10.20.11
Name:   linuxdns-scan.kmccorp.com
Address: 10.10.20.12