Why can't I ping the server from a machine on a different network?
I can't ping the server from a different network. I turned the Internet connection firewall off, but still I can't ping the server from a computer on a different network. I have a Belkin router at home, which supposedly has a double firewall built in. It is NAT + SPI. I have logged into the router but there are no options to turn this off. Do you think this could be causing it?
It could be. The firewall is going to block pings in an attempt to stealth the network and discourage attackers. Many home routers work by means of PAT (Port Address translation). These devices default to allowing traffic from the inside out, but do not allow traffic that originates from the outside in. There should be an advanced user interface page. The settings displayed on this page allow you to open up various port and applications. So, for example, if you wanted to open up ports for the PCAnywhere application this is where you would make that adjustment. You could also open up ports 135-139 and 445 for file and print sharing although I DO NOT RECOMMEND IT as it is a big security risk. Remember if you can access files and folders form outside your network there is the potential that others can too!
This was first published in February 2005