How to assign a different subnet IP address to the inside interface of the PIX if DHCP is enabled on the inside


Wed, 07/22/2009 - 19:35
Jun 18th, 2009

Core issue

The PIX Firewall does not allow you to assign a different IP address on an   inside interface other than the range that is in use by the    Dynamic Host Control Protocol (DHCP) server pool configured on the inside interface.

This is the error message observed:

Interface address is not on same subnet as DHCP pool


The address pool of a PIX Firewall DHCP server must be within the same subnet of the PIX interface that is enabled and you must specify the associated PIX interface with the if_name. In other words, the client must be physically connected to the subnet of a PIX interface.

Use the clear dhcpd command to clear the DHCP pool on the PIX.

For more information, refer to the dhcpd command.

Problem Type

How to (General Information)

Product Family

Firewall - PIX 500 series

Client Location on Network with PIX


Features & Tasks

DHCP server



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