DNS Server Installation Step b

千家信息网最后更新 2025年01月23日DNS Server Installation Step b

DNS Server Installation Step by Step Using CentOS 6.5

DNS, Domain Name System, translates hostnames or URLs into IP addresses. For example if we type www.unixmen.com in browser, the DNS server translates the domain name into its associated ip address. Since the IP addresses are hard to remember, DNS servers are used to translate the hostnames likewww.unixmen.com to 173.xxx.xx.xxx. So it makes easy to remember the domain names instead of its IP address.

Scenario

Primary(Master) DNS Server Details:

Operating System     : CentOS 6.5 serverHostname             : masterdns.unixmen.localIP Address           : 192.168.1.100/24

Secondary(Slave) DNS Server Details:

Operating System     : CentOS 6.5 serverHostname             : secondarydns.unixmen.localIP Address           : 192.168.1.101/24

Client Details:

Operating System     : CentOS 6.5 Desktop  Hostname             : Client.unixmen.localIP Address           : 192.168.1.102/24

Setup Primary(Master) DNS Server

[root@masterdns ~]# yum install bind* -y

1. Configure DNS Server

Add the lines as shown below in '/etc/named.conf' file

[root@masterdns ~]# vi /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; 192.168.1.100; }; ### Master DNS IP ###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; 192.168.1.0/24; }; ### IP Range ### allow-transfer{ localhost; 192.168.1.101; };   ### Slave DNS IP ###recursion yes;dnssec-enable yes;dnssec-validation yes;dnssec-lookaside auto;/* Path to ISC DLV key */bindkeys-file "/etc/named.iscdlv.key";managed-keys-directory "/var/named/dynamic";};logging {        channel default_debug {                file "data/named.run";                severity dynamic;        };};zone "." IN {type hint;file "named.ca";};zone"unixmen.local" IN {type master;file "forward.unixmen";allow-update { none; };};zone"1.168.192.in-addr.arpa" IN {type master;file "reverse.unixmen";allow-update { none; };};include "/etc/named.rfc1912.zones";include "/etc/named.root.key";

2. Create Zone files

Create forward and reverse zone files which we mentioned in the '/etc/named.conf' file.

2.1 Create Forward Zone

Create forward.unixmen file in the '/var/named' directory.

[root@masterdns ~]# vi /var/named/forward.unixmen$TTL 86400@   IN  SOA     masterdns.unixmen.local. root.unixmen.local. (        2011071001  ;Serial        3600        ;Refresh        1800        ;Retry        604800      ;Expire        86400       ;Minimum TTL)@       IN  NS          masterdns.unixmen.local.@       IN  NS          secondarydns.unixmen.local.@       IN  MX 10   mail.unixmen.local.@       IN  A           192.168.1.100@       IN  A           192.168.1.101@       IN  A           192.168.1.102masterdns       IN  A   192.168.1.100secondarydns    IN  A   192.168.1.101client          IN  A   192.168.1.102mail            IN  A    192.168.1.50

2.2 Create Reverse Zone

Create reverse.unixmen file in the '/var/named' directory.

[root@masterdns ~]# vi /var/named/reverse.unixmen $TTL 86400@   IN  SOA     masterdns.unixmen.local. root.unixmen.local. (        2011071001  ;Serial        3600        ;Refresh        1800        ;Retry        604800      ;Expire        86400       ;Minimum TTL)@       IN  NS          masterdns.unixmen.local.@       IN  NS          secondarydns.unixmen.local.@       IN  PTR         unixmen.local.masterdns       IN  A   192.168.1.100secondarydns    IN  A   192.168.1.101client          IN  A   192.168.1.102mail            IN  A   192.168.1.50100     IN  PTR         masterdns.unixmen.local.101     IN  PTR         secondarydns.unixmen.local.102     IN  PTR         client.unixmen.local.50      IN  PTR         mail.unixmen.local.

3. Start the DNS service

[root@masterdns ~]# service named startStarting named:                                            [  OK  ][root@masterdns ~]# chkconfig named on

4. Adjust iptables to allow DNS server from outside of the network

Add the lines as shown below in '/etc/sysconfig/iptables' file.

[root@masterdns ~]# vi /etc/sysconfig/iptables# Firewall configuration written by system-config-firewall# Manual customization of this file is not recommended.*filter:INPUT ACCEPT [0:0]:FORWARD ACCEPT [0:0]:OUTPUT ACCEPT [0:0]-A INPUT -p udp -m state --state NEW --dport 53 -j ACCEPT-A INPUT -p tcp -m state --state NEW --dport 53 -j ACCEPT-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT-A INPUT -p icmp -j ACCEPT-A INPUT -i lo -j ACCEPT-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT-A INPUT -j REJECT --reject-with icmp-host-prohibited-A FORWARD -j REJECT --reject-with icmp-host-prohibitedCOMMIT

5. Restart iptables

[root@masterdns ~]# service iptables restartiptables: Flushing firewall rules:                         [  OK  ]iptables: Setting chains to policy ACCEPT: filter          [  OK  ]iptables: Unloading modules:                               [  OK  ]iptables: Applying firewall rules:                         [  OK  ]

6. Test DNS configuration and zone files for any syntax errors

[root@masterdns ~]# named-checkconf /etc/named.conf [root@masterdns ~]# named-checkzone unixmen.local /var/named/forward.unixmen zone unixmen.local/IN: loaded serial 2011071001OK[root@masterdns ~]# named-checkzone unixmen.local /var/named/reverse.unixmen zone unixmen.local/IN: loaded serial 2011071001OK

7. Test DNS Server

[root@masterdns ~]# dig masterdns.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> masterdns.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49834;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1;; QUESTION SECTION:;masterdns.unixmen.local.INA;; ANSWER SECTION:masterdns.unixmen.local. 86400INA192.168.1.100;; AUTHORITY SECTION:unixmen.local.86400INNSsecondarydns.unixmen.local.unixmen.local.86400INNSmasterdns.unixmen.local.;; ADDITIONAL SECTION:secondarydns.unixmen.local. 86400 INA192.168.1.101;; Query time: 6 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:07:56 2013;; MSG SIZE  rcvd: 114

[root@masterdns ~]# nslookup unixmen.localServer:192.168.1.100Address:192.168.1.100#53Name:unixmen.localAddress: 192.168.1.102Name:unixmen.localAddress: 192.168.1.100Name:unixmen.localAddress: 192.168.1.101

Now the Primary DNS server is ready to use.

Setup Secondary(Slave) DNS Server

[root@secondarydns ~]# yum install bind* -y

1. Configure Slave DNS Server

Open the main configuration file '/etc/named.conf' and add the lines as shown below.

[root@secondarydns ~]# vi /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; 192.168.1.101; };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; 192.168.1.0/24; };recursion yes;dnssec-enable yes;dnssec-validation yes;dnssec-lookaside auto;/* Path to ISC DLV key */bindkeys-file "/etc/named.iscdlv.key";managed-keys-directory "/var/named/dynamic";};logging {        channel default_debug {                file "data/named.run";                severity dynamic;        };};zone "." IN {type hint;file "named.ca";};zone"unixmen.local" IN {type slave;file "slaves/unixmen.fwd";masters { 192.168.1.100; };};zone"1.168.192.in-addr.arpa" IN {type slave;file "slaves/unixmen.rev";masters { 192.168.1.100; };};include "/etc/named.rfc1912.zones";include "/etc/named.root.key";

2. Start the DNS Service

[root@secondarydns ~]# service named startGenerating /etc/rndc.key:                                  [  OK  ]Starting named:                                            [  OK  ][root@secondarydns ~]# chkconfig named on

Now the forward and reverse zones are automatically replicated from Master DNS server to'/var/named/slaves/' in Secondary DNS server.

[root@secondarydns ~]# ls /var/named/slaves/unixmen.fwd  unixmen.rev

[root@secondarydns ~]# cat /var/named/slaves/unixmen.fwd $ORIGIN .$TTL 86400; 1 dayunixmen.localIN SOAmasterdns.unixmen.local. root.unixmen.local. (2011071001 ; serial3600       ; refresh (1 hour)1800       ; retry (30 minutes)604800     ; expire (1 week)86400      ; minimum (1 day))NS masterdns.unixmen.local.NS secondarydns.unixmen.local.A192.168.1.100A192.168.1.101A192.168.1.102$ORIGIN unixmen.local.clientA192.168.1.102masterdnsA192.168.1.100secondarydnsA192.168.1.101

[root@secondarydns ~]# cat /var/named/slaves/unixmen.rev $ORIGIN .$TTL 86400; 1 day1.168.192.in-addr.arpaIN SOAmasterdns.unixmen.local. root.unixmen.local. (2011071001 ; serial3600       ; refresh (1 hour)1800       ; retry (30 minutes)604800     ; expire (1 week)86400      ; minimum (1 day))NS masterdns.unixmen.local.NS secondarydns.unixmen.local.PTRunixmen.local.$ORIGIN 1.168.192.in-addr.arpa.100PTRmasterdns.unixmen.local.101PTRsecondarydns.unixmen.local.102PTRclient.unixmen.local.clientA192.168.1.102masterdnsA192.168.1.100secondarydnsA192.168.1.101

3. Add the DNS Server details to all systems

[root@secondarydns ~]# vi /etc/resolv.conf# Generated by NetworkManagersearch ostechnix.comnameserver 192.168.1.100nameserver 192.168.1.101nameserver 8.8.8.8

4. Test DNS Server

[root@secondarydns ~]# dig masterdns.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> masterdns.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21487;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1;; QUESTION SECTION:;masterdns.unixmen.local.INA;; ANSWER SECTION:masterdns.unixmen.local. 86400INA192.168.1.100;; AUTHORITY SECTION:unixmen.local.86400INNSmasterdns.unixmen.local.unixmen.local.86400INNSsecondarydns.unixmen.local.;; ADDITIONAL SECTION:secondarydns.unixmen.local. 86400 INA192.168.1.101;; Query time: 15 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:27:57 2013;; MSG SIZE  rcvd: 114

[root@secondarydns ~]# dig secondarydns.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> secondarydns.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20958;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1;; QUESTION SECTION:;secondarydns.unixmen.local.INA;; ANSWER SECTION:secondarydns.unixmen.local. 86400 INA192.168.1.101;; AUTHORITY SECTION:unixmen.local.86400INNSmasterdns.unixmen.local.unixmen.local.86400INNSsecondarydns.unixmen.local.;; ADDITIONAL SECTION:masterdns.unixmen.local. 86400INA192.168.1.100;; Query time: 4 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:31:53 2013;; MSG SIZE  rcvd: 114

[root@secondarydns ~]# nslookup unixmen.localServer:192.168.1.100Address:192.168.1.100#53Name:unixmen.localAddress: 192.168.1.101Name:unixmen.localAddress: 192.168.1.102Name:unixmen.localAddress: 192.168.1.100

Client Side Configuration

Add the DNS server details in '/etc/resolv.conf' file in all client systems

[root@client unixmen]# vi /etc/resolv.conf# Generated by NetworkManagersearch unixmen.localnameserver 192.168.1.100nameserver 192.168.1.101nameserver 8.8.8.8

Test DNS Server

[root@client unixmen]# dig masterdns.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6 <<>> masterdns.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19496;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1;; QUESTION SECTION:;masterdns.unixmen.local.INA;; ANSWER SECTION:masterdns.unixmen.local. 86400INA192.168.1.100;; AUTHORITY SECTION:unixmen.local.86400INNSmasterdns.unixmen.local.unixmen.local.86400INNSsecondarydns.unixmen.local.;; ADDITIONAL SECTION:secondarydns.unixmen.local. 86400 INA192.168.1.101;; Query time: 30 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:47:55 2013;; MSG SIZE  rcvd: 114

[root@client unixmen]# dig secondarydns.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6 <<>> secondarydns.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14852;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1;; QUESTION SECTION:;secondarydns.unixmen.local.INA;; ANSWER SECTION:secondarydns.unixmen.local. 86400 INA192.168.1.101;; AUTHORITY SECTION:unixmen.local.86400INNSsecondarydns.unixmen.local.unixmen.local.86400INNSmasterdns.unixmen.local.;; ADDITIONAL SECTION:masterdns.unixmen.local. 86400INA192.168.1.100;; Query time: 8 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:48:38 2013;; MSG SIZE  rcvd: 114

[root@client unixmen]# dig client.unixmen.local; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6 <<>> client.unixmen.local;; global options: +cmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14604;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2;; QUESTION SECTION:;client.unixmen.local.INA;; ANSWER SECTION:client.unixmen.local.86400INA192.168.1.102;; AUTHORITY SECTION:unixmen.local.86400INNSmasterdns.unixmen.local.unixmen.local.86400INNSsecondarydns.unixmen.local.;; ADDITIONAL SECTION:masterdns.unixmen.local. 86400INA192.168.1.100secondarydns.unixmen.local. 86400 INA192.168.1.101;; Query time: 5 msec;; SERVER: 192.168.1.100#53(192.168.1.100);; WHEN: Thu Mar  7 13:49:11 2013;; MSG SIZE  rcvd: 137

[root@client unixmen]# nslookup unixmen.localServer:192.168.1.100Address:192.168.1.100#53Name:unixmen.localAddress: 192.168.1.102Name:unixmen.localAddress: 192.168.1.100Name:unixmen.localAddress: 192.168.1.101

Now the primary and secondary DNS servers are ready.