Netgear DGND3300 Manual Do Utilizador

5-8

Customizing Your Network Settings

The default DMZ server feature is helpful when using some online games and videoconferencing 
applications that are incompatible with Network Address Translation (NAT). The 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 modem router unless the traffic is a 
response to one of your local computers or a service that you have configured in the Port 
Forwarding/Port Triggering 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.

The WAN Setup screen lets you configure a default DMZ server.

To assign a computer or server to be a default DMZ server: 

1. In the last Default DMZ Server field, type the last digit of the IP address for that computer. 

To remove the default DMZ server, enter 0 (zero).

2. Select the Default DMZ Server check box, and click Apply.

Respond to Ping on Internet 
WAN Port

If you want the modem router to respond to a ping from the Internet, select this 
check box. This should be used only as a diagnostic tool, since it allows your 
modem router to be discovered. Do not select this check box unless you have 
a specific reason to do so.

MTU Size (in bytes)

The normal MTU (Maximum Transmit Unit) value for most Ethernet networks 
is 1500 bytes, or 1492 Bytes for PPPoE connections. For some ISPs you 
might need to reduce the MTU. This is rarely required, and should not be done 
unless you are sure it is necessary for your ISP connection. See 

Disable 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.

Warning: DMZ servers pose a security risk. A computer designated as the default DMZ 

server loses much of the protection of the firewall and is exposed to exploits 
from the Internet. If compromised, the DMZ server computer can be used to 
attack other computers on your network.