Operation Manual

Networking

N150 and N300 Wireless Routers

MTU only if you are sure that it is necessary for your ISP connection. See Change the

MTU Size on page 21.

• NAT Filtering. 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. By default,

the Secured radio button is selected.

- Open NAT provides a much less secured firewall, but allows almost all Internet

applications to function.

• Disable SIP ALG. Some Voice over IP (VoIP) applications do not function well with

the Session Initiation Protocol (SIP) Application Layer Gateway (ALG). Selecting the

check box to turn off the SIP ALG might enable connected VoIP devices to create and

accept a VoIP call through the router. By default, this check box is cleared.

• Disable IGMP Proxying. IGMP proxying allows computers on the LAN to receive the

multicast traffic they are subscribed to from the Internet. By default, this check box is

selected, and the IGMP proxy is disabled, preventing multicast traffic from the Internet

to the LAN. Clear the Disable IGMP Proxying check box to allow multicast traffic

from the Internet to the LAN.

• VPN Passthrough. The router supports VPN passthrough for IPSec, PPTP, and

L2TP.

- IPSec Passthrough. To enable or disable IPSec passthrough, select the Enable

or Disabled radio button.

- PPTP Passthrough. To enable or disable PPTP passthrough, select the Enable

or Disabled radio button.

• L2TP Passthrough. To enable or disable L2TP passthrough, select the Enable or

Disabled radio button.

5. Change the settings as needed.

6. Click the Apply button.

Your changes are saved.

Set 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 other applications might not function well. In some cases, one local

computer can run the application correctly if the IP address for that computer is entered as

the default DMZ server.