Need more information on DMZ effect.

[Nekurahn]

Good evening everyone.

I am playing Final Fantasy XI on my laptop and I am getting an FFXI-4001 error, which has been identified as a problem pertaining to my router. Because of my router model, I am being told that to fix this problem, the only way is to turn off the DMZ on my router. I would like to know what DMZ does and what consequences this will have for my laptop and pc using internet through it.

Thank you for your time, have nice day.

 

[Ph30nIX]

DMZ is a setting on a router that is used to expose a single computer directly to the internet, rather than hiding it using NAT etc.

Check for the DMZ setting on your router, and change it to the opposite of whatever it is.

 

[DelJo63]

DMZ Description

A DMZ is a special network topology (layout/wiring) like:

Internet --- firewall 
               ^   |
               ^   +------ Public Server        (hidden ports)
               ^   (ports 22, 25, 80 )  ---- proxy ----- firewall-router ----- Company Lan Systems
               ^       Public Progams                   ^
               ^                                        ^
               ==========================================
                   The DMZ area

Access into the Compan Lan is hidden in two ways;

1- non-public ip addresses
2- non-standard ports​

The Proxy is the only place the mapping of external to internal services is known
and as a result, EVEN if the firewall is breached, it is impossible to make entry into
the Lan systems. A worst case intrusion is handled by complete tear down of the
systems within the DMZ and reinstalling everything, including the OS.

The net effect is to minimize losses and work to get running (safely) again.

 

[Nekurahn]

So there is no consequence for a home-user? The way I understand it, it would only have consequence in a business environment with a large network. Am I correct?

 

[DelJo63]

You can use that setup too; but what would be in the DMZ and are you prepared to
Proxy services from the DMZ across the second firewall?

As stated in another post, the DMZ setting on the router (the one closest to the ISP)
allows direct access to the system attached. At home you would need:

ISP ---- router(dmz setting)---switch--Game System
                               +
                               |
                               +---2nd router--- other lan systems

to avoid the Proxy issue

 

[Nekurahn]

This is what I have:

ISP ----- router(dmz setting) ----- PC (wired)
...........................I
...........................I
...........................+----- Laptop (wireless)
...........................I
...........................I
...........................+----- Xbox 360 (wired)

What effect will turning off the DMZ of my router have on me?

 

[DelJo63]

As is, the Laptop and Xbox are also exposed for trojans and direct attacks.

The firewalls on all systems are your sole protection.

 

[Nekurahn]

So turning off DMZ would do nothing in my case?

 

[DelJo63]

you would likely need to port forward to the game machine the ports used by your games.

It would actually INCREASE your securtity to have it off