Welcome to our page. In this page we are going to discuss about Domain Name Server(DNS) configuration. Later the same DNS configuration going to use Oracle 11g Release 2 Real Application Cluster (RAC) Installations.
Step 1 : Login as root and install below listed Bind RPM’s.
rpm -Uvh bind-9.3.3-7.el5.i386.rpm \
bind-chroot-9.3.3-7.el5.i386.rpm \
bind-devel-9.3.3-7.el5.i386.rpm \
bind-libbind-devel-9.3.3-7.el5.i386.rpm \
bind-libs-9.3.3-7.el5.i386.rpm \
bind-sdb-9.3.3-7.el5.i386.rpm \
system-config-bind-4.0.3-2.el5.noarch.rpm \
caching-nameserver-9.3.3-7.el5.i386.rpm \
postgresql-libs-8.1.4-1.1.i386.rpm
Step 2: Verify the IP address for the DNS server. Use following command to check the IP address.
[[email protected] ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:7D:60:F3
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0inet6 addr: fe80::20c:29ff:fe7d:60f3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:28 errors:0 dropped:0 overruns:0 frame:0
TX packets:39 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4919 (4.8 KiB) TX bytes:5628 (5.4 KiB)
Interrupt:67 Base address:0x2024
Step 3: There are four files we have to edit. Find the below easy steps to configure the DNS server.
1. Create a named.conf file using sample named.caching-nameserver.conf file.
[[email protected] ~]# cd /var/named/chroot/etc/
[[email protected] etc]# ls
localtime named.caching-nameserver.conf named.rfc1912.zones rndc.key
[[email protected] etc]#cp named.caching-nameserver.conf named.conf
2. Edit the named.conf file based on your configuration. For example.
options{
listen-on port 53 { 192.168.1.100; };
# 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”;
// Those options should be used carefully because they disable port
// randomization
// query-source port 53;
// query-source-v6 port 53;
allow-query { any; };
allow-query-cache { localhost; };
};
logging {
channel default_debug {
file “data/named.run”;
severity dynamic;
};
};
view localhost_resolver {
match-clients { any; };
match-destinations { 192.168.1.100; };
recursion yes;
include “/etc/named.rfc1912.zones”;
};
3. Edit named.rfc1912.zones file. Sample file given below.
zone “.” IN {
type hint;
file “named.ca”;
};
zone “india.com” IN {
type master;
file “forward.zone”;
allow-update { none; };
};
zone “localhost” IN {
type master;
file “localhost.zone”;
allow-update { none; };
};
zone “1.168.192.in-addr.arpa” IN {
type master;
file “reverse.zone”;
allow-update { none; };
};
..
4. Change the permission to the above two files.
chgrp named named.conf
5. Change the directory to below location
cd /var/named/chroot/var/named
cp localdomain.zone forward.zone
cp named.local reverse.zone
6. Modify the forward.zone file. example
$TTL 86400
@ IN SOA dnc.india.com. root.dnc.india.com. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS dnc.india.com.
dnc IN A 192.168.1.100
7. Modify the reverse.zone file
$TTL 86400
@ IN SOA dnc.india.com. root.dnc.india.com. (
1997022700 ; Serial
28800 ; Refresh
14400 ; Retry
3600000 ; Expire
86400 ) ; Minimum
IN NS dnc.india.com.
100 IN PTR dnc.india.com.
8. Change the ownership for both the files.
chgrp named reverse.zone
chgrp named forward.zone
9. make an entry to both /etc/hosts and /etc/resolv.conf files. The samples are below.
cat /etc/hosts
192.168.1.100 dnc.india.com dnc
cat /etc/resolve.conf
search india.com
namedserver 192.168.1.100
10. Restart the named services using below statement.
service named restart
11. Verify the DNS server using below statements
[[email protected] named]# dig dnc.india.com
; «» DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 «» dnc.india.com
;; global options: printcmd
;; Got answer:
;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 1483
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;dnc.india.com. IN A
;; ANSWER SECTION:
dnc.india.com. 86400 IN A 192.168.1.100
;; AUTHORITY SECTION:
india.com. 86400 IN NS dnc.india.com.
;; Query time: 1 msec
;; SERVER: 192.168.1.100#53(192.168.1.100)
;; WHEN: Mon Aug 27 23:54:49 2012
;; MSG SIZE rcvd: 61
12. To check reverse the zone
[[email protected] named]# dig -x 192.168.1.100
; «» DiG 9.3.6-P1-RedHat-9.3.6-4.P1.el5_4.2 «» -x 192.168.1.100
;; global options: printcmd
;; Got answer:
;; -»HEADER«- opcode: QUERY, status: NOERROR, id: 55949
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 1, ADDITIONAL: 1
;; QUESTION SECTION:
;100.1.168.192.in-addr.arpa. IN PTR
;; ANSWER SECTION:
100.1.168.192.in-addr.arpa. 86400 IN PTR dnc-priv.india.com.
100.1.168.192.in-addr.arpa. 86400 IN PTR dnc.india.com.
;; AUTHORITY SECTION:
1.168.192.in-addr.arpa. 86400 IN NS dnc.india.com.
;; ADDITIONAL SECTION:
dnc.india.com. 86400 IN A 192.168.1.100
;; Query time: 1 msec
;; SERVER: 192.168.1.100#53(192.168.1.100)
;; WHEN: Mon Aug 27 23:57:27 2012
;; MSG SIZE rcvd: 124
13. To verify DNS Server using nslookup
[[email protected] named]# nslookup dnc.india.com
Server: 192.168.1.100
Address: 192.168.1.100#53
Name: dnc.india.com
Address: 192.168.1.100
DNS server working fine now. Finally we got success.
14. For Oracle 11gR2 RAC Installation adding node Information in /var/named/chroot/var/named/forward.zone file on DNS server.
$TTL 86400
@ IN SOA dnc.india.com. root.dnc.india.com. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS dnc.india.com.
dnc IN A 192.168.1.100
kracnode1 IN A 192.168.1.50
kracnode2 IN A 192.168.1.51
kracnode1-vip IN A 192.168.1.60
kracnode2-vip IN A 192.168.1.61
kracnode-scan IN A 192.168.1.70
kracnode-scan IN A 192.168.1.71
kracnode-scan IN A 192.168.1.72
15. Restart named service as a root user.
[[email protected] named]# service named restart
Stopping named: [ OK ]
Starting named: [ OK ]
16. Verify the SCAN names using nslookup.
[[email protected] named]# nslookup kracnode-scan
Server: 192.168.1.100
Address: 192.168.1.100#53
Name: kracnode-scan.india.com
Address: 192.168.1.72
Name: kracnode-scan.india.com
Address: 192.168.1.70
Name: kracnode-scan.india.com
Address: 192.168.1.71
17. Add below files in /etc/resolv.conf file on all the nodes.
search india.com
nameserver 192.168.1.100
[[email protected] ]# cat /etc/resolv.conf
search india.com
nameserver 192.168.1.100
[[email protected] bin]# nslookup kracnode-scan
Server: 192.168.1.100
Address: 192.168.1.100#53
Name: kracnode-scan.india.com
Address: 192.168.1.71
Name: kracnode-scan.india.com
Address: 192.168.1.72
Name: kracnode-scan.india.com
Address: 192.168.1.70
18. DNS server ready for Oracle 11gR2 RAC setup go ahead and start RAC installation using below blog.
