After the Routing and Remote Access Service has been configured, it is important to make sure that ISA Server is also configured to allow VPN traffic through the firewall so remote clients can connect. This is not required for dial-up connections.

To configure the firewall to allow VPN connections, run the Small Business Server Internet Connection Wizard and enable virtual private networking in the firewall configuration component.
It is also necessary to enable IP routing and to allow PPTP to pass through the firewall so that remote clients are able to access resources across the firewall as well.

To set IP routing and enable PPTP pass through

1. Open ISA Management. (Click Start, and then click Small Business Server Administrator Console. Double-click Internet Security and Acceleration Server.)
2. Double-click Access Policy.
3. Right-click IP Packet Filters, and then select Properties.
4. On the General tab, select Enable IP routing.
5. On the PPTP tab, select PPTP through ISA firewall.
6. Click OK.