Setup DNS for RAC 12c implementation in virtual Box

If you are plan to implement rac setup in virtul box for your lab practise, you need to setup a dns configuration necessary steps to use single client access name (SCAN) introduced in 11gR2 RAC.

The DNS setup may be a separate server, or you can make it on any one of the nodes you’re preparing for rac implementation.

Here I have chosed to setup on rac first node, so you need to do some setup here

RAC First node :

Step 1:

Below rpm package need to installed on rac first node.

[root@racnode1 ~]# rpm -qa|grep bind
bind-libs-9.3.6-20.P1.el5_8.6
bind-9.3.6-20.P1.el5_8.6
system-config-bind-4.0.3-6.el5
bind-utils-9.3.6-20.P1.el5_8.6

 

Step 2:

check named.conf file available in /etc/ and also /var/named, If it’s not available, Please copy those files from

[root@racnode1 etc]# pwd
/usr/share/doc/bind-9.3.6/sample/etc
[root@racnode1 etc]# ls
named.conf named.conf.bkp named.rfc1912.zones named.root.hints rndc.conf
[root@racnode1 etc]# cp * /etc

 

[root@racnode1 etc]# cd ..
[root@racnode1 sample]# cd var
[root@racnode1 var]# ls
named var
[root@racnode1 var]# cp -r named /var

 

Step 3: edit the file like below

[root@racnode1 var]# cat /etc/named.conf
//
// Sample named.conf BIND DNS server ‘named’ configuration file
// for the Red Hat BIND distribution.
//
// See the BIND Administrator’s Reference Manual (ARM) for details, in:
// file:///usr/share/doc/bind-*/arm/Bv9ARM.html
// Also see the BIND Configuration GUI : /usr/bin/system-config-bind and
// its manual.
//
options
{
// Those options should be used carefully because they disable port
// randomization
// query-source port 53;
// query-source-v6 port 53;

// Put files that named is allowed to write in the data/ directory:
directory “/var/named”; // the default
dump-file “data/cache_dump.db”;
statistics-file “data/named_stats.txt”;
// memstatistics-file “data/named_mem_stats.txt”;
forwarders {192.168.1.1;};

};
key ddns_key
{
algorithm hmac-md5;
secret “gTsUbdMeXIAIOfeSUO6abZ2LkFqwOu3gKHih1Y4jqNEJeQXnnBM8S1xx”;
};

zone “racnode.com” IN {
type master;
file “racnode.com.zone”;
allow-update { none; };
};

zone “1.168.192.in-addr.arpa.” IN {
type master;
file “1.168.192.in-addr.arpa”;
allow-update { none; };
};

Step 4:  Create entries in zone file

[root@racnode1 named]# cat 1.168.192.in-addr.arpa

$TTL 86400
$ORIGIN 1.168.192.in-addr.arpa.

@ IN SOA racnode1.racnode.com. root.racnode.com.( 2
3H
1H
1W
1H )
IN NS 192.168.1.101
IN NS 192.168.1.1
101 IN PTR racnode1.racnode.com.
102 IN PTR racnode2.racnode.com.
111 IN PTR racnode1-vip.racnode.com.
112 IN PTR racnode2-vip.racnode.com.
201 IN PTR rac-scan.racnode.com.
202 IN PTR rac-scan.racnode.com.
203 IN PTR rac-scan.racnode.com.

 

[root@racnode1 named]# cat racnode.com.zone
$TTL 86400
@ IN SOA racnode.com. racnode.com.(
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
racnode.com. IN NS 192.168.1.101
localhost IN A 127.0.0.1
racnode1.racnode.com. IN A 192.168.1.101
racnode2.racnode.com. IN A 192.168.1.102
racnode1-vip.racnode.com. IN A 192.168.1.111
racnode2-vip.racnode.com. IN A 192.168.1.112
rac-scan.racnode.com. IN A 192.168.1.201
rac-scan.racnode.com. IN A 192.168.1.202
rac-scan.racnode.com. IN A 192.168.1.203

 

Step 5: Start the named service

 

[root@racnode1 named]# service named start
Starting named: [ OK ]

[root@racnode1 named]# chkconfig named on

Step 6: resolv.conf looks like below

[root@racnode1 named]# cat /etc/resolv.conf

search racnode.com
nameserver 192.168.1.101
options timeout:1
options attempts:2

Step 6:

[root@racnode1 named]# nslookup rac-scan
Server: 192.168.1.101
Address: 192.168.1.101#53

Name: rac-scan.racnode.com
Address: 192.168.1.203
Name: rac-scan.racnode.com
Address: 192.168.1.201
Name: rac-scan.racnode.com
Address: 192.168.1.202

Step 7:  Go to  second node

[root@racnode2 ~]# service named status
named is stopped
[root@racnode2 ~]# cat /etc/resolv.conf
search racnode.com

nameserver 192.168.1.101

options timeout:1
options attempts:2

[root@racnode2 ~]# nslookup rac-scan
Server: 192.168.1.101
Address: 192.168.1.101#53

Name: rac-scan.racnode.com
Address: 192.168.1.201
Name: rac-scan.racnode.com
Address: 192.168.1.202
Name: rac-scan.racnode.com
Address: 192.168.1.203

 

Step 8: /etc/hosts file look like below on each node but don’t added scan address here

[root@racnode1 named]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost
::1 localhost.localdomain localhost6 localhost
# Public
192.168.1.101 racnode1.racnode.com racnode1 racnode1
192.168.1.102 racnode2.racnode.com racnode2
# Private
10.10.1.1 racnode1-priv.racnode.com racnode1-priv
10.10.1.2 racnode2-priv.racnode.com racnode2-priv
# Virtual
192.168.1.111 racnode1-vip.racnode.com racnode1-vip
192.168.1.112 racnode2-vip.racnode.com racnode2-vip

 

Step 9:

[root@racnode1 named]# grep ^hosts /etc/nsswitch.conf
hosts: files dns