Cisco Router as DHCP Relay Agent

How to make your Cisco Router as DHCP relay agent

R1#configure terminal
R1(config)#interface fastethernet 1/1
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface fastethernet 1/1.10
R1(config-subif)#encapsulation dot1q 10
R1(config-subif)#ip address 192.168.10.1 255.255.255.0
R1(config-subif)#no shutdown
R1(config-subif)#ip helper-address 192.168.20.2
R1(config-if)#exit
R1(config)#interface fastethernet 1/1.20
R1(config-subif)#encapsulation dot1q 20
R1(config-subif)#ip address 192.168.20.1 255.255.255.0
R1(config-subif)#no shutdown

Cisco Router as DHCP Server

How to make your Cisco Router as DHCP server

R1#configure terminal

R1(config)#ip dhcp pool NET-192.168.1.0
R1(dhcp-config)#default-router 192.168.1.1
R1(dhcp-config)#dns-server 192.168.1.2
R1(dhcp-config)#network 192.168.1.0 255.255.255.0
R1(dhcp-config)#exit
R1(config)#ip dhcp excluded-address 192.168.1.1 192.168.1.10