Why can I connect to or ping some computers via my Cisco VPN connection but not others?
Why can I connect to or ping some computers via my Cisco VPN connection but not others? I use Remote Desktop Connection to connect to various computers on our corporate network (Windows XP PRO on all machines and each one has been allowed to receive remote connections.). When I try to connect to the problem computers, I get the following error message: "The client could not connect to the remote computer."
If I open and log into the Cisco VPN 3000 manager on the Internet, I can actually ping the IP addresses. But if I log into a VPN connection through a remote Cisco system VPN Client Connection, open the command prompt and ping the same IP addresses, the request times out. However, I can ping other IP addresses on our network through both sources. Any suggestions as to how I might resolve this problem so I can connect to all the computers?
You can only connect to some. Is it always the same computers that fail? RDC is an "If you please" operation. And with Microsoft's predilection for remembering the last decision, any time the computer says no to an outside connection, that becomes the default. For security, that is exactly what you want to happen. For remote management, it is a pain.
Pings are pings are not pings. The end of the VPN tunnel is a construct and not real hardware. This can lead to some really baffling symptoms. First, check any forwarding or filtering rules for access limitations. Second, is DNS working? Is it working correctly? Third, remember that XP SP2 turns on the firewall by default and does NOT allow ICMP (pings).
This was first published in September 2005