Here is a small draft steps in order to allow you to setup and configure DHCP server on Unix/Ubuntu.
If anything to improve or comment, please put your comment in below.
Install DHCP server Packet 

sudo apt-get install isc-dhcp-server

 

Enable DHCP server Network Interface

Enable the DCHP server on your network interface (in my case eth0):

sudo nano /etc/default/isc-dhcp-server

Set INTERFACES="" to the name of the network interface that you want to enable the DHCP server on:
<em>INTERFACES="eth0"</em>

Configuration

Edit the DHCP server configuration:

mv /etc/dhcp/dhcpd.conf /etc/dhcp/dhcpd.conf.org
sudo nano /etc/dhcp/dhcpd.conf

## ddns-update-style none; default-lease-time 600; max-lease-time 7200; option domain-name "test.lan"; option domain-name-servers 1.1.1.1; authoritative; log-facility local7; subnet 1.1.1.0 netmask 255.255.255.0 { option routers 1.1.1.254;}

Restart Service

sudo service isc-dhcp-server restart

 

Configure DHCP Reservation 

ddns-update-style none; default-lease-time 600; max-lease-time 7200; option domain-name "test.lan"; option domain-name-servers 1.1.1.1; authoritative; log-facility local7; subnet 1.1.1.0 netmask 255.255.255.0 { option routers 1.1.1.254; option ntp-servers 1.1.1.1; option netbios-node-type 8; pool { deny unknown-clients; range 1.1.1.10 2.1.1.13; } }

####===Reservation MAC address===####
host xp-client

{

hardware ethernet 08:00:27:50:1c:21;

fixed-address 1.1.1.11;

}