DHCP lab in GNS3 | How to Configure DHCP on Cisco Router

Cisco DHCP Configuration | How to assign automatic IP address from Cisco Router:

In this article I will show you how to configure and enable DHCP (Dynamic Host Configuration Protocol) on Gns3 router. For this lab I have Create the following lab in which I have configure a router (DHCP Server) as DHCP server where as I used the two DHCP clients which will obtain the IP address automatically from DHCP server. These DHCP clients include a router (which is configured like a PC) and a VM machine.  You can visit How to connect windows VM to Gns3 & installation of windows 10 on Virtualbox for more detail.

Following configuration are required for making the Router as DHCP server.

DHCP server (R1) Configuration:

R1#enable

R1#Configure t

R1 config)#ip dhcp pool ipranges

R1(dhcp-config)# network 100.1.11.0 255.255.255.0

R1(dhcp-config)#dns server 100.1.11.1

 R1(dhcp-config)#default-router 100.1.11.1

R1(dhcp-config)#lease 10 (this command will set the IP lease for 10 day, view more Cisco Commands)

How to exclude the IP addresses from DHCP range

R1(dhcp-config)#ip dhcp excluded-addresses 100.1.11.20 100.1.11.31

Following are the configuration required on router which will act as DHCP client.

PC2 Configuration:

PC2#enable

PC2#Configure t

PC21#no ip routing

PC2#inf f0/0

PC2#ip address dhcp

 PC2#no shutdown

VM win 10 DHCP client configurations:

Simple power on the VM host in DHCP and set the network adapter setting to obtain the IP automatically. Check the following images:

How to test DHCP configurations:

On DHCP server use the following command for confirming DHCP configurations

show ip dhcp binding

Following will be the output in our case.

Other command that you can use is:

show DHCP neighbor.