I currently have a remote XP client trying to access our new vpn network from a remote location. The XP client is behind an at&t u-verse router. The flow diagram is below. I currently get a message on the XP client that GRE is not enabled or something of the sort, and it gets stuck on username and password verifying.
XP computer (192.168.1.100)
AT&t u-verse router (public ip)
Linksys RV082(192.168.0.1, public ip) configured with VPN passthrough enabled and portfowarded to allow pptp
Cisco 2821(192.168.0.100, 192.168.4.1) port fowared to allow pptp
Windows XP VPN server(192.168.4.91)
Yes i do know that the 2821 can do vpn however I was asked to do it this way.
How would i configure the 2821 (firewall is enabled) and what eles may need to be changed.