Hiding Your Computer from Ping

As part of my quest to figure out how to run an open home network safely, I've come across this useful tidbit worth passing on:

The Sygate Firewall (amongst others) has a vulnerability.

My IT put me on to this (this is a funny guy who is Chinese but speaks with a Russian accent because he comes from some far off province on the Russian border).

Your computer should be invisible to "pings" (messages from cyberspace which essentially say "knock, knock - are you there?"). Everyone should ensure that their firewall stops responses to these signals. In this way, your computer will remain invisible to sniffers.

For Sygate, this vulnerability is easily corrected as follows:

Click Tools, Advanced Rules and click the Add button. At Rule Description you enter ICMP (Internet Control Message Protocol). The Action has to be Block this traffic. At the tab Ports and Protocols you select ICMP from the combo box, and then the Select All button. Furthermore change the Traffic Direction in Incoming and click OK. - source

Labels: firewall, network, security