Tutorial description

This tutorial will show you how to configure dynamic IP address assignment on multiple VLAN with a unique DHCP server appliance on the network.

Two VLANs are configured on Switch0 with Router0 as default gateway :

  • VLAN 10 - Nework : 192.168.10.0/24 - Gateway : 192.168.10.1 (FA 0/0.10)
  • VLAN 20 - Network : 192.168.20.0/24 - Gateway : 192.168.20.1 (FA 0/0.20)

The unique DHCP server is located on a remote subnet with IP 172.16.24.2.

DHCP lab overview on cisco packet tracer 7.3

 

Learning DHCP : recommended books

Coming soon

 

DHCP configuration

Declare IP address pools on the DHCP management tab of the server like on the picture below. One pool has to be declared for each VLAN. Don't forget to configure the right network settings and default gateway (Router0 FA 0/0.10 and FA 0.0.20 IP address) for each VLAN.

DHCP server configuration in cisco packet tracer 8.0

 

Configure router0 for DHCP forwarding to the DHCP server (DHCP relay)

The ip helper-address <IP address> configures DHCP request forwarding to the configured <IP address> DHCP server.

Router(config)# interface FastEthernet0/0.10
Router(config-subif)# encapsulation dot1Q 10
Router(config-subif)# ip address 192.168.10.1 255.255.255.0
Router(config-subif)# ip helper-address 172.16.24.2

Router(config)# interface FastEthernet0/0.20
Router(config-subif)# encapsulation dot1Q 20
Router(config-subif)# ip address 192.168.20.1 255.255.255.0
Router(config-subif)# ip helper-address 172.16.24.2