DNS

Using bind on ubuntu:

Network Setup:

Step 1: Install BIND

First, update your package lists and install BIND9:

sudo apt update
sudo apt install bind9 dnsutils

Step 2: Configure the DNS Zone for team2.net

Need to configure the forward and reverse DNS zones for team2.net.

Forward Zone File Configuration

Navigate to the BIND directory

cd /etc/bind

Create the forward zone file for team2.net. First, open the named configuration file to define the zone:

sudo nano named.conf.local

Add the following zone definition:

zone "team2.net" {
    type master;
    file "/etc/bind/zones/db.team2.net";
};

Create the directory for your zones if it doesn't already exist:

sudo mkdir /etc/bind/zones

Next, create and edit the zone file:

sudo nano /etc/bind/zones/db.team2.net

Add the following records to the zone file:

$TTL    604800
@       IN      SOA     ns1.team2.net. admin.team2.net. (
                           2         ; Serial
                      604800         ; Refresh
                       86400         ; Retry
                     2419200         ; Expire
                      604800 )       ; Negative Cache TTL
; Name servers
@       IN      NS      ns1.team2.net.

; A records for name server and other hosts
ns1     IN      A       192.168.2.12
www     IN      A       192.168.2.5
db      IN      A       192.168.2.7

Step 3: Reverse Zone File Configuration

This step is optional but recommended for resolving IP addresses back to hostnames.

Define the reverse zone in named.conf.local:

sudo nano named.conf.local

Add the reverse zone configuration:

zone "2.168.192.in-addr.arpa" {
    type master;
    file "/etc/bind/zones/db.192.168.2";
};

Create the reverse zone file:

sudo nano /etc/bind/zones/db.192.168.2

Add reverse mappings:

$TTL    604800
@       IN      SOA     team2.net. admin.team2.net. (
                           2         ; Serial
                      604800         ; Refresh
                       86400         ; Retry
                     2419200         ; Expire
                      604800 )       ; Negative Cache TTL
@       IN      NS      ns1.team2.net.
12      IN      PTR     ns1.team2.net.
5       IN      PTR     www.team2.net.
7       IN      PTR     db.team2.net.

Step 4: Check Configuration and Restart BIND

After setting up your zone files, check the configuration for errors:

sudo named-checkconf
sudo named-checkzone team2.net /etc/bind/zones/db.team2.net
sudo named-checkzone 2.168.192.in-addr.arpa /etc/bind/zones/db.192.168.2

If everything is configured correctly, restart BIND to apply changes:

sudo systemctl restart bind9

Step 5: Test DNS Server

Use dig or nslookup to test your DNS server and ensure it's resolving domain names correctly:

dig @192.168.2.12 www.team2.net +short
dig -x 192.168.2.5 @192.168.2.12 +short

Final Config Output:

Config "/etc/bind/named.conf.local"

//
// 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 "team2.net" {
    type master;
    file "/etc/bind/zones/db.team2.net";
};
zone "2.168.192.in-addr.arpa" {
    type master;
    file "/etc/bind/zones/db.192.168.2";
};

Config "/etc/bind/zones/db.team2.net"

TTL    604800
@       IN      SOA     ns1.team2.net. admin.team2.net. (
                           2         ; Serial
                      604800         ; Refresh
                       86400         ; Retry
                     2419200         ; Expire
                      604800 )       ; Negative Cache TTL
; Name servers
@       IN      NS      ns1.team2.net.

; A records for name server and other hosts
ns1     IN      A       192.168.2.12
www     IN      A       192.168.2.5
db      IN      A       192.168.2.7

Config "/etc/bind/zones/db.192.168.2"

TTL    604800
@       IN      SOA     team2.net. admin.team2.net. (
                           2         ; Serial
                      604800         ; Refresh
                       86400         ; Retry
                     2419200         ; Expire
                      604800 )       ; Negative Cache TTL
@       IN      NS      ns1.team2.net.
12      IN      PTR     ns1.team2.net.
5       IN      PTR     www.team2.net.
7       IN      PTR     db.team2.net.