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New Member

Cisco ASA5505 - DMZ Connection

My first time programming a Cisco ASA - Have to get my feet wet sometime right?

Anyways I''m trying to setup up Ethernet 0/6 to be a DMZ Connection

When I add port 0/6 to DMZ it gives me an error saying "The IP Address X.X.X.X /Subnet Mask cannot overlap the subnet of interface outside"

So my question is I have an outside connection already configured - How can I make a DMZ connection with the same subnet mask with a different IP?

New Member

Cisco ASA5505 - DMZ Connection

Hello Kevin,

You will need to setup the DMZ interface in a different subnet using an address range from RFC1918 (,, and then NAT traffic from the 'dmz' to the 'outside'. You will also need to modify the access-lists accordingly.

Please post your config and I'd be happy to get you pointed in the right direction, also -- please indicate whether you are using a base or security plus license and what software version you are running (both items can be found by issuing "show version").