Netgear WNR3500v2 WNR3500v2 User Manual - Page 68

NETGEAR RangeMax™ Wireless-N Gigabit Router WNR3500v2 User Manual Table 5-2. WAN Setup Settings Setting MTU Size (in bytes) NAT Filtering Description 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 "Changing the MTU Size" on page 6-6. Network Address Translation (NAT) determines how the router processes inbound traffic. Secured NAT provides a secured firewall to protect the computers on the LAN from attacks from the Internet, but might prevent some Internet games, point-to-point applications, or multimedia applications from functioning. Open NAT provides a much less secured firewall, but allows almost all Internet applications to function. Setting Up a 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 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. 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. Incoming traffic from the Internet is usually discarded by the 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. 5-8 Customizing Your Network Settings v1.0, May 2009