Using this page, you can set up a Default DMZ Server and allow the router to respond to a 'ping' from the internet. Both of these options have security issues, so use them carefully.
Connect Automatically, as Required
Normally, this option should be enabled. An Internet connection will
be made automatically after each timeout, whenever Internet-bound traffic
is detected. This provides connection on demand and is potentially cost-saving.
If disabled, you must connect manually, using the "Connection Status" button on the Router Status screen. This manual connection will stay up all the time without timeouts.
Respond To Ping On Internet Port
If you want the Router to respond to a 'Ping' from the Internet, click this check box. This can be used as a diagnostic tool. Again, like the DMZ server, this can be a security problem. You shouldn't check this box unless you have a specific reason to do so.
MTU Size
The normal MTU (Maximum Transmit Unit) value for most Ethernet networks is 1500 Bytes, 1454 Bytes for PPPoE connections. For some ISPs you may need to reduce the MTU. But this is rarely required, and should not be done unless you are sure it is necessary for your ISP connection.