DNS SERVER

DNS configure without CHROOT on RHEL/OEL For Oracle RAC


[root@dns1 ~]# rpm -qa | grep -i bind
ypbind-1.19-12.el5_6.1
kdebindings-3.5.4-6.el5
bind-utils-9.3.6-20.P1.el5_8.6
system-config-bind-4.0.3-6.0.1.el5
bind-libs-9.3.6-20.P1.el5_8.6
bind-9.3.6-20.P1.el5_8.6

[root@dns1 ~]# hostname
dns1.testenv.com



----- Create/Edit /etc/named.conf File ------

[root@dns1 ~]# cat /etc/named.conf
options {
        listen-on port 53 { 192.168.2.200; };
        directory "/var/named";
        dump-file "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        /*
         * If there is a firewall between you and nameservers you want
         * to talk to, you might need to uncomment the query-source
         * directive below.  Previous versions of BIND always asked
         * questions using port 53, but BIND 8.1 uses an unprivileged
         * port by default.
         */
         // query-source address * port 53;

        // My Additions
        // Forwarder: Anything this DNS can't resolve gets forwarded to my ISPs DNS.
        #forwarders { 194.168.4.100; 194.168.8.100; };
        // End My Additions
};

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

zone "2.168.192.in-addr.arpa." IN {
        type master;
        file "2.168.192.in-addr.arpa";
        allow-update { none; };
};

include "/etc/rndc.key";




----------- Create/Edit /var/named/2.168.192.in-addr.arpa File ----------------
[root@dns1 named]# pwd
/var/named
[root@dns1 named]# cat 2.168.192.in-addr.arpa
$ORIGIN 2.168.192.in-addr.arpa.
$TTL 1H
@          IN     SOA    testenv.com.  root.testenv.com. (
                         42 ; serial (d. adams)
                         3H ; refresh
                        15M ; retry
                         1W ; expiry
                         1D ) ; minimum

2.168.192.in-addr.arpa.   IN   NS     testenv.com.
151 IN PTR rac1.testenv.com.
152 IN PTR rac2.testenv.com.
161 IN PTR rac1-vip.testenv.com.
162 IN PTR rac2-vip.testenv.com.
51  IN PTR rac-scan.testenv.com.
52  IN PTR rac-scan.testenv.com.
53  IN PTR rac-scan.testenv.com.


------------------ Create/Edit /var/named/testenv.com.zone File --------

[root@dns1 named]# cat testenv.com.zone
$TTL    86400
@               IN SOA  testenv.com root.testenv.com (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum
                IN NS   testenv.com
rac1            IN A    192.168.2.151
rac2            IN A    192.168.2.152
rac1-priv       IN A    192.168.3.151
rac2-priv       IN A    192.168.3.152
rac1-vip        IN A    192.168.2.161
rac2-vip        IN A    192.168.2.162
rac-scan        IN A    192.168.2.51
rac-scan        IN A    192.168.2.52
rac-scan        IN A    192.168.2.53



-------- Give the Ownership --------

cd /var/named
chown named:named 2.168.192.in-addr.arpa
chown named:named testenv.com.zone

chkconfig named on

[root@dns1 named]# cat /etc/resolv.conf
nameserver 192.168.2.200



--------- Check the its working or not ----------

[root@dns1 named]# nslookup rac-scan
Server:         192.168.2.200
Address:        192.168.2.200#53

Name:   rac-scan.testenv.com
Address: 192.168.2.53
Name:   rac-scan.testenv.com
Address: 192.168.2.51
Name:   rac-scan.testenv.com
Address: 192.168.2.52


[root@dns1 named]# dig testenv.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5_8.6 <<>> testenv.com
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50541
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;testenv.com.                   IN      A

;; AUTHORITY SECTION:
testenv.com.            86400   IN      SOA     testenv.com.testenv.com. root.testenv.com.testenv.com. 42 10800 900 604800 86400

;; Query time: 3 msec
;; SERVER: 192.168.2.200#53(192.168.2.200)
;; WHEN: Wed Jul  5 11:31:57 2017
;; MSG SIZE  rcvd: 82


---------------------------------------------------------------------------------------------------------------------------
=============
Now RAC Part
=============


Configure one node if working well athen follow all steps on all nodes.

[root@rac1 ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               rac1.testenv.com rac1 localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6
#Public-IP
192.168.2.151  rac1  rac1.testenv.com
192.168.2.152  rac2  rac2.testenv.com

#Virtual-IP
192.168.2.161  rac1-vip      rac1-vip.testenv.com
192.168.2.162 rac2-vip      rac2-vip.testenv.com

#Scan-IP
192.168.198.51  rac-scan        rac-scan.testenv.com
192.168.2.52    rac-scan        rac-scan.testenv.com
192.168.2.53    rac-scan        rac-scan.testenv.com

192.168.2.200   dns1    dns1.testenv.com


[root@rac1 ~]# hostname
rac1.testenv.com


[root@rac1 ~]# cat /etc/resolv.conf
search testenv.com      dns1.testenv.com
nameserver 192.168.2.200


[root@rac1 ~]# dig rac1

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> rac1
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 63859
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;rac1.                          IN      A

;; Query time: 4 msec
;; SERVER: 192.168.2.200#53(192.168.2.200)
;; WHEN: Wed Jul  5 11:36:32 2017
;; MSG SIZE  rcvd: 22



[root@rac1 ~]# dig rac-scan

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> rac-scan
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 359
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;rac-scan.                      IN      A

;; Query time: 13 msec
;; SERVER: 192.168.2.200#53(192.168.2.200)
;; WHEN: Wed Jul  5 11:36:05 2017
;; MSG SIZE  rcvd: 26



Now its working fine ... above the setting replicate on all nodes.