I have a Cisco 877 router which connects my network to the Internet using an ADSL line, a single public IP address and NAT; the IOS version is 15.

Everything is working ok, but I'd like to configure this router to be a VPN server, to be able to connect to the network from the outside.

I've tried looking for documentation, but everything I can find is related to having the 877 act as a VPN client, or to site-to-site VPNs; I can't find anything about letting single remote computers access the internal network, which is something I can do quite easily using Windows' RRAS or ISA Server.

• Can the Cisco 877 act as a VPN server for remote client computers? (Looks like it should, but just to be sure...)
• Which type of VPNs does it support? Do they require some special software on the client machines, or can they be used by standard out-of-the-box Windows computers?
• And, finally: how to set up this?