Why does the ping command not work after Service Pack 2 is installed?
Windows XP Service Pack 2 enables the Windows Firewall by default. The ping command works by sending Internet Control Message Protocol (ICMP) requests. For security reasons, Windows Firewall defaults to dropping all ICMP requests, and thus pinging a computer with Service Pack 2 installed results in a “Request timed out” message. To enable ICMP requests for ping to work on a computer with Windows XP Service Pack 2 installed, use the following steps. • From the Start menu, click Control Panel. • In Control Panel, click Security Center. • In Windows Security Center, in the Manage Security Settings For area, click Windows Firewall . • In the Windows Firewall window, click the Advanced tab, and then in the ICMP area click Settings. • In the ICMP Settings dialog box, select Allow incoming echo request, and then click OK.
