User's Manual

NETGEAR genie Advanced Home
42
N300 Wireless ADSL2+ Modem Router DGN2200v4
NAT provides a much less secured firewall, but allows almost all Internet applications to
function.
• 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. Select the Disable
SIP ALG check box to disable the SIP ALG. Disabling the SIP ALG might be useful when
running certain applications.
• Disable IGMP Proxying. The IGPM Proxying feature lets a LAN computer receive the
multicast traffic directed to it from the Internet. Selecting this check box prevents this from
occurring.
Default DMZ Server
The default DMZ server feature is helpful when you are using some online games and
videoconferencing applications that are incompatible with Network Address Translation
(NAT). The modem routerrecognizes some of these applications and works 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.
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.
The router usually detects and discards Incoming traffic from the Internet that is not a
response to one of your local computers or a service that you have set up in the Port
Forwarding/Port Triggering screen. Instead of discarding this traffic, you can have the router
forward the traffic to one computer on your network. This computer is called the default DMZ
server.
 To set up a default DMZ server:
1. On the WAN Setup screen, select the Default DMZ Server check box.
2. Type the IP address.
3. Click Apply.
Change the MTU Size
The Maximum Transmission Unit (MTU) is the largest data packet a network device
transmits. When one network device communicates across the Internet with another, the data
packets travel through many devices along the way. If a device in the data path has a lower
MTU setting than the other devices, the data packets are split or “fragmented” to
accommodate the device with the smallest MTU.