Help! Vpn Connnection

Good day guys,

I need PPTP VPN to access to my school network，but is facing some difficulty with the connection. I'm currently using Suse 10.3. and have already installed NetworkManager-pptp.

I also have the default SuseFirewall running. My school VPN requires the following port & protocol to work and to pass through the Firewall.
i. TCP port 1723 or PPTP and
ii. Generic Routing Encapsulation (GRE) protocol for VPN channel

Any advice on it? How do I obtain the log file or error message from the VPN client?

Thanks,
Prueba