Chapter 5: Advanced Configuration
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N300 Wireless Gigabit ADSL2+ Modem Router DGN3500 User Manual
Setting Up a Default DMZ Server
The default demilitarized zone (DMZ) server feature is helpful when you use some online
games and video confrencing applications that are incompatible with NAT. The wireless
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.
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.
Incoming traffic from the Internet is usually discarded by the wireless 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.
Log in to the wireless modem router at its default LAN address of
http://192.168.0.1
with its default user name of
admin
and default password of
password
, or using
whatever user name, password, and LAN address you have chosen for the wireless
modem router.
2.
In the main menu, under Advanced, click WAN Setup to display the following screen.
3.
On the WAN Setup screen, select the
Default DMZ Server
check box.
4.
Type the IP address for that server.
5.
Click
Apply
to save your changes.
The LAN Setup screen allows configuration of LAN IP services such as Dynamic Host
Configuration Protocol (DHCP) and Routing Information Protocol (RIP).
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.
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.
Setting
Description
