User's Manual

Wireless-N 300 Modem Router DGN2200 User Manual
Advanced Configuration 6-3
v1.0, November 2009
Setting Up a Default DMZ Server
The default demilitarized zone (DMZ) server feature is helpful when you use some online games
and videoconferencing applications that are incompatible with NAT. The wireless-N modem router
is programmed to recognize some of these applications and to work correctly with them, but there
are other applications that might not function well. In some cases, one local computer can run the
application correctly if that computer’s IP address is entered as the default DMZ server.
Incoming traffic from the Internet is usually discarded by the wireless-N modem router unless the
traffic is a response to one of your local computers or a service that you have configured in the
Ports screen. Instead of discarding this traffic, you can have it forwarded to one computer on your
network. This computer is called the default DMZ server.
To assign a computer or server to be a default DMZ server:
1. In the main menu, under Advanced, select WAN Setup to display the following screen.
Disabling the SIP ALG The Session Initiation Protocol (SIP) Application Level Gateway (ALG)
is enabled by default to optimize VoIP phone calls that use the SIP. The
Disable SIP ALG check box allows you to disable the SIP ALG.
Disabling the SIP ALG might be useful when running certain
applications.
Note: For security reasons, you should avoid using the default DMZ server feature. When
a computer is designated as the default DMZ server, it loses much of the protection
of the firewall, and is exposed to many exploits from the Internet. If compromised,
the computer can be used to attack your network.
Table 6-1. WAN Settings (continued)
Setting Description