Question : VPN Not working via Wifi

If I use AT&T 3G on my iphone 3GS, I get access to VPN - all works fine.  If I use my home wifi via my home wireless internet connection (wireless cable modem - motorola sbg900 gateway) my VPN on the iphone does not work -- i get the message "VPN Connection - Negotiation with the VPN server failed."   Is there something i need to change on the gateway?

Answer : VPN Not working via Wifi

also some routers/modems are problematic with VPNs in general, sometimes a firmware upgrade can help.

I hope this helps !