Configuring a BOOTP/DHCP relay gateway

The DHCP relay agent selects the lowest-numbered IP address on the interface to use for DHCP messages. The DHCP server then uses this IP address when it assigns client addresses. However, this IP address may not be the same subnet as the one on which the client needs the DHCP service.

This feature provides a way to configure a gateway address for the DHCP relay agent to use for DHCP requests, rather than the DHCP relay agent automatically assigning the lowest-numbered IP address.

You must be in VLAN context to use this command, for example:

switch# config
switch(config)# vlan 1
switch(vlan-1)#

Syntax:


ip bootp-gateway ip-addr

Allows you to configure an IP address for the DHCP relay agent to use for DHCP requests. The IP address must have been configured on the interface.

Default: Lowest-numbered IP address

If the IP address has not already been configured on the interface (VLAN), you will see the message shown in the following example.

Example of trying to configure an IP address that is not on this interface (VLAN)

switch# config
switch(config)# vlan 1
switch(vlan-1)# ip bootp-gateway 10.10.10.1
The IP address 10.10.10.1 is not configured on this VLAN.