C
OMMAND
L
INE
I
NTERFACE
4-158
Command Mode
Interface Configuration (VLAN)
Command Usage
This command is used to configure DHCP relay functions for host
devices attached to the switch. If DHCP relay service is enabled, and
this switch sees a DHCP request broadcast, it inserts its own IP address
into the request so the DHCP server will know the subnet where the
client is located. Then, the switch forwards the packet to the DHCP
server on another network. When the server receives the DHCP
request, it allocates a free IP address for the DHCP client from its
defined scope for the DHCP client’s subnet, and sends a DHCP
response back to the DHCP relay agent (i.e., this switch). This switch
then broadcasts the DHCP response received from the server to the
client.
Example
In the following example, the device is reassigned the same address.
Related Commands
ip dhcp relay server (3-158)

ip dhcp relay server

Use this command to specify the addresses of DHCP servers to be used by
the switch’s DHCP relay agent. Use the no form to clear all addresses.
Console(config)#interface vlan 1
Console(config-if)#ip dhcp relay
Console(config-if)#end
Console#show ip interface
Vlan 1 is up, addressing mode is Dhcp
Interface address is 10.1.0.254, mask is 255.255.255.0, Primary
MTU is 1500 bytes
Proxy ARP is disabled
Split horizon is enabled
Console#