Linksys routers disable the WAN ping function by default as a security precaution. When a host is connected directly to the Internet without a firewall in place, it presents a security risk because an attacker can learn of the host's existence through a ping sweep. It is not bad in itself for a host on the Internet to be pinged, as long as a firewall is in place. The Linksys router acts as a firewall for the rest of the network by default. You can enable the WAN ping on a Linksys router through the administrative interface.
Open a browser, then type "192.168.1.1" (without quotes) into the address bar. Press "Enter."
Leave the user name blank and type "admin" for the password. Press "Enter."
Click to uncheck "Filter anonymous Internet requests."
Click "Save Settings" to apply the changes.
Though the router can now be pinged from the Internet, it is still acting as an SPI firewall to help protect the network.