Step by step DNS Configuration on Linux RHEL5/OEL5
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 \
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
[root@dnc ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:7D:60:F3
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 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
eth0 Link encap:Ethernet HWaddr 00:0C:29:7D:60:F3
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 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.
[root@dnc ~]# cd /var/named/chroot/etc/
[root@dnc etc]# ls
localtime named.caching-nameserver.conf named.rfc1912.zones rndc.key
[root@dnc 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";
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;
// 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";
};
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";
};
zone "." IN {
type hint;
file "named.ca";
};
zone "india.com" IN {
type master;
file "forward.zone";
allow-update { none; };
};
type master;
file "forward.zone";
allow-update { none; };
};
zone "localhost" IN {
type master;
file "localhost.zone";
allow-update { none; };
};
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.
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
[root@dnc 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
;; 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
;dnc.india.com. IN A
;; ANSWER SECTION:
dnc.india.com. 86400 IN A 192.168.1.100
dnc.india.com. 86400 IN A 192.168.1.100
;; AUTHORITY SECTION:
india.com. 86400 IN NS dnc.india.com.
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
;; SERVER: 192.168.1.100#53(192.168.1.100)
;; WHEN: Mon Aug 27 23:54:49 2012
;; MSG SIZE rcvd: 61
[root@dnc 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
;; 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
;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.
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.
1.168.192.in-addr.arpa. 86400 IN NS dnc.india.com.
;; ADDITIONAL SECTION:
dnc.india.com. 86400 IN A 192.168.1.100
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
;; 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
[root@dnc 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
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.
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.
16. Verify the SCAN names using nslookup.
17. Add below files in /etc/resolv.conf file on all the nodes.
18. DNS server ready for Oracle 11gR2 RAC setup go ahead and start RAC installation using below blog.
Oracle 11gR2 RAC Installation Steps on Linux
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[root@dnc
named]# service named restart
Stopping
named:
[ OK ]
Starting
named:
[ OK ]
16. Verify the SCAN names using nslookup.
[root@dnc
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
[oracle@krac1
]# cat /etc/resolv.conf
search
india.com
nameserver
192.168.1.100
[root@krac1
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.
Oracle 11gR2 RAC Installation Steps on Linux
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