Setup DNS Server On Debian 7 Wheezy
What is DNS Server?
As you might know, DNS, Domain Name System, is a system that resolves Domain names into IP Addresses and vice-versa. For example if you type www.unixmen.com in your browser, the computer doesn’t know actually where it is. So your computer will contact the current DNS server to find where www.unixmen.com is. The DNS servers simply reply to your computer with the associated IP address of unixmen.com domain. Since IP address of every domain is hard to remember, DNS Server makes it easy to remember domain names instead of their IP addresses. You can get the DNS server details from your Internet Service Providers.
Types of DNS Server
There are two types of DNS Servers, Primary and Secondary DNS server. These two DNS servers are computers where the domain names with their respective IP addresses are stored and the information available on both DNS servers is identical. The values for these two DNS’s are configured by the Internet Service Provider (ISP). The secondary DNS acts as backup for the Primary DNS if Primary DNS server is down.
Scenario
In this tutorial i am going to setup local Primary and secondary DNS servers. I am using two systems running with Debian 7 for primary and secondary DNS server and one system running with Ubuntu 13.04 Desktop for Client.
Primary DNS server details:
Operating System: Debian 7 Wheezy Server Hostname: master.unixmen.local IP Address: 192.168.1.200/24Secondary DNS Server Details:
Operating System: Debian 7 Wheezy Desktop Hostname: slave.unixmen.local IP Address: 192.168.1.201/24Client Details:
Operating System: Ubuntu 13.04 Desktop Hostname: client.unixmen.local IP Address: 192.168.1.100/24Note: I tested this how-to twice on local area network (LAN). It is worked for me as i expected. If you want to setup external DNS server, use your public ip in zone files and dns configuration files.
1. Setup Primary DNS Server
Install bind9
BIND (Berkely Internet Name Domain) is a software for translating domain names into IP addresses.
Install it using command:
apt-get install bind9 bind9utils bind9-doc dnsutilsThe DNS configuration files are stored in the /etc/bind directory. The primary configuration file is /etc/bind/named.conf.
Configure Bind9
Open up the file /etc/bind/named.conf.local in any editor.
nano /etc/bind/named.conf.localAdd the following lines to define forward and reverse zone files.
zone "unixmen.local" { type master; file "/etc/bind/for.unixmen.local"; }; zone "1.168.192.in-addr.arpa" { type master; file "/etc/bind/rev.unixmen.local"; };Save and close the file.
Create Zone Files
Now create the forward and reverse zone files which we defined in the above step.
1. Forward Zone file
Copy the existing zone file template /etc/bind/db.local to create a new forward zone file.
cp /etc/bind/db.local /etc/bind/for.unixmen.localNow edit the file /etc/bind/for.unixmen.local,
nano /etc/bind/for.unixmen.localChange the contents as shown below and replace the domain name and ip address with your own.
; ; BIND data file for forward.unixmen.local zone ; $TTL 604800 @ IN SOA master.unixmen.local. root.unixmen.local. ( 2 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL IN A 192.168.1.200 ; @ IN NS master.unixmen.local. @ IN NS slave.unixmen.local. @ IN A 192.168.1.200 @ IN A 192.168.1.201 @ IN A 192.168.1.100 @ IN AAAA ::1 master IN A 192.168.1.200 slave IN A 192.168.1.201 client IN A 192.168.1.1002. Reverse Zone file
Copy the existing zone file template /etc/bind/db.127 to create a new reverse zone file.
cp /etc/bind/db.127 /etc/bind/rev.unixmen.localNow edit the file /etc/bind/rev.unixmen.local,
nano /etc/bind/rev.unixmen.localChange the contents as shown below and replace the domain name and ip address with your own.
; ; BIND reverse data file for rev.unixmen.local ; $TTL 604800 @ IN SOA master.unixmen.local. root.unixmen.local. ( 3 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL ; @ IN NS master. @ IN NS slave. @ IN A 192.168.1.200 @ IN A 192.168.1.201 @ IN A 192.168.1.100 200 IN PTR master.unixmen.local. 201 IN PTR slave.unixmen.local. 100 IN PTR client.unixmen.local.Save and close the file.
As you see in the above configuration, i increased the serial number for reverse zone file. For each change you should increase the reverse zone serial number as well.
Now restart bind9 service.
service bind9 restartTest DNS Configuration and Zone Files
You can check the DNS configuration and zone files configuration for any syntax errors.
Check DNS configuration file using command:
named-checkconf /etc/bind/named.conf.localIf it returns nothing, your configuration file doesn’t have any syntax errors.
Check Forward Zone:
named-checkzone unixmen.local /etc/bind/for.unixmen.localSample Output:
zone unixmen.local/IN: loaded serial 2 OKCheck Reverse Zone:
named-checkzone unixmen.local /etc/bind/rev.unixmen.localSample output:
zone unixmen.local/IN: loaded serial 3 OKAdjust iptables to allow DNS default port 53
First make sure that BIND9 is running on default port 53.
netstat -tulpn | grep :53Sample output:
tcp 0 0 192.168.1.200:53 0.0.0.0:* LISTEN 4893/named tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 4893/named tcp6 0 0 :::53 :::* LISTEN 4893/named udp 0 0 192.168.1.200:53 0.0.0.0:* 4893/named udp 0 0 127.0.0.1:53 0.0.0.0:* 4893/named udp 0 0 0.0.0.0:5353 0.0.0.0:* 2582/avahi-daemon: udp6 0 0 :::53 :::* 4893/named udp6 0 0 :::5353 :::* 2582/avahi-daemon:Now let us open port 53 through iptables.
First Install iptables-persistent package using command:
apt-get install iptables-persistentOpen up the file /etc/iptables/rules.v4 using any editor,
nano /etc/iptables/rules.v4,Add the rule to open port 53.
# Generated by iptables-save v1.4.14 on Tue Nov 5 13:20:11 2013 *filter :INPUT ACCEPT [468:43718] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [374:41531] :fail2ban-ssh - [0:0] -A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh -A INPUT -p tcp -m multiport --dports 22 -j fail2ban-ssh -A INPUT -p tcp -m state --state NEW --dport 53 -j ACCEPT -A fail2ban-ssh -j RETURN -A fail2ban-ssh -j RETURN COMMIT # Completed on Tue Nov 5 13:20:11 2013Start or restart iptables-persistent service.
service iptables-persistent restartNow check port 53 is open or not using command:
iptables -L -nSample output:
Chain INPUT (policy ACCEPT) target prot opt source destination fail2ban-ssh tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 22 fail2ban-ssh tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 22 fail2ban-ssh tcp -- 0.0.0.0/0 0.0.0.0/0 multiport dports 22 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:53 Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination Chain fail2ban-ssh (3 references) target prot opt source destination RETURN all -- 0.0.0.0/0 0.0.0.0/0 RETURN all -- 0.0.0.0/0 0.0.0.0/0 RETURN all -- 0.0.0.0/0 0.0.0.0/0As you see in the above command, port 53 is open. Now your local clients will be able to resolve hostnames.
Test Master DNS Server
Edit file /etc/resolv.conf,
nano /etc/resolv.confAnd add your Master DNS server details,
search unixmen.local nameserver 192.168.1.200Reboot the system or restart the networking service.
service networking restartNow let us check Master DNS server is working or not using the following commands:
Method 1:
dig master.unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> master.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51823 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1 ;; QUESTION SECTION: ;master.unixmen.local. IN A ;; ANSWER SECTION: master.unixmen.local. 604800 IN A 192.168.1.200 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS master.unixmen.local. unixmen.local. 604800 IN NS slave.unixmen.local. ;; ADDITIONAL SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 ;; Query time: 14 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 5 19:31:18 2013 ;; MSG SIZE rcvd: 104Method 2:
dig -x master.unixmen.localSample Output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> -x master.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 48100 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;local.unixmen.master.in-addr.arpa. IN PTR ;; Query time: 31 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 5 19:30:37 2013 ;; MSG SIZE rcvd: 51Method 3:
dig unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65339 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;unixmen.local. IN A ;; ANSWER SECTION: unixmen.local. 604800 IN A 192.168.1.100 unixmen.local. 604800 IN A 192.168.1.200 unixmen.local. 604800 IN A 192.168.1.201 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS master.unixmen.local. unixmen.local. 604800 IN NS slave.unixmen.local. ;; ADDITIONAL SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 master.unixmen.local. 604800 IN A 192.168.1.200 ;; Query time: 11 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Tue Nov 5 13:31:22 2013 ;; MSG SIZE rcvd: 152Method 4:
dig -x unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> -x unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 3681 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;local.unixmen.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: in-addr.arpa. 3600 IN SOA b.in-addr-servers.arpa. nstld.iana.org. 2011029787 1800 900 604800 3600 ;; Query time: 1590 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Tue Nov 5 13:31:36 2013 ;; MSG SIZE rcvd: 112Method 5:
nslookup unixmen.localSample output:
Server: 192.168.1.200 Address: 192.168.1.200#53 Name: unixmen.local Address: 192.168.1.100 Name: unixmen.local Address: 192.168.1.200 Name: unixmen.local Address: 192.168.1.201Method 6:
host unixmen.localSample output:
unixmen.local has address 192.168.1.200 unixmen.local has address 192.168.1.201 unixmen.local has address 192.168.1.100 unixmen.local has IPv6 address ::1Method 7:
host master.unixmen.localSample Output:
master.unixmen.local has address 192.168.1.200That’s it. Primary DNS server is ready and working.
2. Setup Secondary DNS Server
Install bind9 package with following command:
apt-get install bind9 bind9utils bind9-doc dnsutilsConfigure DNS Server
Before proceeding to configure Secondary DNS server, first you should allow the zone transfer from your Primary DNS server.
To do so, go to Primary DNS server, edit the DNS main configuration file /etc/bind/named.conf.local,
nano /etc/bind/named.conf.localAdd the lines allow-transfer { 192.168.1.201; }; and also-notify { 192.168.1.201; }; in the zone section.
// // Do any local configuration here // // Consider adding the 1918 zones here, if they are not used in your // organization //include "/etc/bind/zones.rfc1918"; zone "unixmen.local" { type master; file "/etc/bind/for.unixmen.local"; allow-transfer { 192.168.1.201; }; also-notify { 192.168.1.201; }; }; zone "1.168.192.in-addr.arpa" { type master; notify no; file "/etc/bind/rev.unixmen.local"; allow-transfer { 192.168.1.201; }; also-notify { 192.168.1.201; }; };Here 192.168.1.201 is Secondary DNS server IP address. allow-transfer { 192.168.1.201; }; line will transfer the zone files automatically from master dns to secondary dns server. also-notify { 192.168.1.201; }; line will notify the secondary dns server if any changes in primary dns server zone files. Save and close the file.
Now go to Secondary DNS server, edit file /etc/bind/named.conf.local,
nano /etc/bind/named.conf.localAdd the lines as shown below.
// // Do any local configuration here // // Consider adding the 1918 zones here, if they are not used in your // organization //include "/etc/bind/zones.rfc1918"; zone "unixmen.local" { type slave; file "/var/cache/bind/for.unixmen.local"; masters { 192.168.1.200; }; }; zone "1.168.192.in-addr.arpa" { type slave; file "/var/cache/bind/rev.unixmen.local"; masters { 192.168.1.200; }; };Here 192.168.1.200 is my Primary DNS server IP address. Save and close the file.
Adjust iptables to allow DNS default port 53
First make sure that BIND9 is running on default port 53.
netstat -tulpn | grep :53Sample output:
tcp 0 0 192.168.1.200:53 0.0.0.0:* LISTEN 4893/named tcp 0 0 127.0.0.1:53 0.0.0.0:* LISTEN 4893/named tcp6 0 0 :::53 :::* LISTEN 4893/named udp 0 0 192.168.1.200:53 0.0.0.0:* 4893/named udp 0 0 127.0.0.1:53 0.0.0.0:* 4893/named udp 0 0 0.0.0.0:5353 0.0.0.0:* 2582/avahi-daemon: udp6 0 0 :::53 :::* 4893/named udp6 0 0 :::5353 :::* 2582/avahi-daemon:Check the port 53 is open using command:
iptables -L -nIf port 53 is not open, do the following steps.
First Install iptables-persistent package using command:
apt-get install iptables-persistentOpen up the file /etc/iptables/rules.v4 using any editor,
nano /etc/iptables/rules.v4,Add the rule to open port 53.
# Generated by iptables-save v1.4.14 on Tue Nov 5 14:23:49 2013 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -p tcp -m state --state NEW --dport 53 -j ACCEPT COMMIT # Completed on Tue Nov 5 14:23:49 2013Start or restart iptables-persistent service.
service iptables-persistent restartNow check port 53 is open or not using command:
iptables -L -nSample output:
Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:53 Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destinationAs you see in the above command, port 53 is open. Now your local clients will be able to resolve hostnames.
Now restart the bind9 service with command:
service bind9 restartNow the zone files from master server will be replicated to secondary server automatically. The zones files will be created in /var/cache/bind folder of secondary server.
ls /var/cache/bind/Sample output:
for.unixmen.local managed-keys.bind managed-keys.bind.jnl rev.unixmen.localCheck Forward zone file:
cat /var/cache/bind/for.unixmen.localSample output:
$ORIGIN . $TTL 604800 ; 1 week unixmen.local IN SOA master.unixmen.local. root.unixmen.local. ( 2 ; serial 604800 ; refresh (1 week) 86400 ; retry (1 day) 2419200 ; expire (4 weeks) 604800 ; minimum (1 week) ) NS slave.unixmen.local. NS master.unixmen.local. A 192.168.1.100 A 192.168.1.200 A 192.168.1.201 AAAA ::1 $ORIGIN unixmen.local. client A 192.168.1.100 master A 192.168.1.200 slave A 192.168.1.201Check Reverse Zone file:
cat /var/cache/bind/rev.unixmen.localSample output:
$ORIGIN . $TTL 604800 ; 1 week 1.168.192.in-addr.arpa IN SOA master.unixmen.local. root.unixmen.local. ( 3 ; serial 604800 ; refresh (1 week) 86400 ; retry (1 day) 2419200 ; expire (4 weeks) 604800 ; minimum (1 week) ) NS slave. NS master. $ORIGIN 1.168.192.in-addr.arpa. 100 PTR client.unixmen.local. 200 PTR master.unixmen.local. 201 PTR slave.unixmen.local.Test Secondary DNS Server
Edit file /etc/resolv.conf,
nano /etc/resolv.confAnd add your Master DNS server details,
search unixmen.local nameserver 192.168.1.200 nameserver 192.168.1.201Reboot the system or restart the networking service.
service networking restartNow let us check Master DNS server is working or not using the following commands:
Method 1:
dig slave.unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> slave.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53146 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1 ;; QUESTION SECTION: ;slave.unixmen.local. IN A ;; ANSWER SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS slave.unixmen.local. unixmen.local. 604800 IN NS master.unixmen.local. ;; ADDITIONAL SECTION: master.unixmen.local. 604800 IN A 192.168.1.200 ;; Query time: 11 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 20:04:35 2013 ;; MSG SIZE rcvd: 104Method 2:
dig -x slave.unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> -x slave.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 8652 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;local.unixmen.slave.in-addr.arpa. IN PTR ;; Query time: 4010 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 20:05:34 2013 ;; MSG SIZE rcvd: 50Method 3:
dig unixmen.localSample Output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9642 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;unixmen.local. IN A ;; ANSWER SECTION: unixmen.local. 604800 IN A 192.168.1.200 unixmen.local. 604800 IN A 192.168.1.201 unixmen.local. 604800 IN A 192.168.1.100 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS slave.unixmen.local. unixmen.local. 604800 IN NS master.unixmen.local. ;; ADDITIONAL SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 master.unixmen.local. 604800 IN A 192.168.1.200 ;; Query time: 11 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 20:03:08 2013 ;; MSG SIZE rcvd: 152Method 4:
dig -x unixmen.localSample output:
; <<>> DiG 9.8.4-rpz2+rl005.12-P1 <<>> -x unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 34729 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;local.unixmen.in-addr.arpa. IN PTR ;; Query time: 4006 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 20:03:58 2013 ;; MSG SIZE rcvd: 44Method 5:
nslookup unixmen.localSample output:
Server: 192.168.1.200 Address: 192.168.1.200#53 Name: unixmen.local Address: 192.168.1.201 Name: unixmen.local Address: 192.168.1.100 Name: unixmen.local Address: 192.168.1.200Method 6:
host unixmen.localSample output:
unixmen.local has address 192.168.1.100 unixmen.local has address 192.168.1.200 unixmen.local has address 192.168.1.201 unixmen.local has IPv6 address ::1Method 7:
host slave.unixmen.localSample output:
slave.unixmen.local has address 192.168.1.201Method 8:
host master.unixmen.localSample output:
master.unixmen.local has address 192.168.1.200That’s it. Secondary DNS server is ready and up now.
Client Side Configuration
In your client system, edit file /etc/resolv.conf,
sudo nano /etc/resolv.confComment out all existing DNS servers and add the your Primary and Secondary DNS servers IP addresses.
search unixmen.local nameserver 192.168.1.200 nameserver 192.168.1.201Test DNS Server
Run the following command to test Primary DNS server.
dig master.unixmen.localSample output:
; <<>> DiG 9.9.2-P1 <<>> master.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47844 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;master.unixmen.local. IN A ;; ANSWER SECTION: master.unixmen.local. 604800 IN A 192.168.1.200 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS master.unixmen.local. unixmen.local. 604800 IN NS slave.unixmen.local. ;; ADDITIONAL SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 ;; Query time: 5 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 22:59:52 2013 ;; MSG SIZE rcvd: 115Check Secondary server using command:
dig slave.unixmen.localSample output:
; <<>> DiG 9.9.2-P1 <<>> slave.unixmen.local ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16506 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;slave.unixmen.local. IN A ;; ANSWER SECTION: slave.unixmen.local. 604800 IN A 192.168.1.201 ;; AUTHORITY SECTION: unixmen.local. 604800 IN NS slave.unixmen.local. unixmen.local. 604800 IN NS master.unixmen.local. ;; ADDITIONAL SECTION: master.unixmen.local. 604800 IN A 192.168.1.200 ;; Query time: 3 msec ;; SERVER: 192.168.1.200#53(192.168.1.200) ;; WHEN: Mon Nov 4 23:00:25 2013 ;; MSG SIZE rcvd: 115That’s it. Now you’ve successfully installed Primary and Secondary DNS servers.
Cheers!
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