Networks

What type of router / firewall / modem?
What features does it have for setting security?
what type of access do external users need?
how many external users?

That is what VPN is for. PPTP or L2TP tunneling protocol with encryption, ACLs to set up who can access and, most importantly, who CAN'T.

if you have windows xp pro the easiest way would be through remote desktop. If you have nt server or 2000 server use terminal services with IPSec VPN. Or try PCAnywhere by Symantec. If they just need file access you can use an FTP server or a web server... many options

The first question I have to ask is if your ISP issues you a static or dynamic IP address. If it is a dynamic addressing system, it still is possible for you to set up an external connection, but it makes it much more difficult.

Once you have determined the IP address, then that will indicate the type of VPN/Firewall/Login you will need to set up. (Unless you are not concerned with security of your network.)

At present, a cable modem provided by comcast, a linksys router and a black ice firewall.

Five people currently need access.

Todd

I hate to say it, but in all of the research I've done the last couple of days, there isn't an easy solution for a dynamic IP address VPN host.

What I have found is that if both ends of the VPN are dynamic IP addresses, you will need to use one of the Dynamic DNS providers. I did a search for Dynamic DNS that list many providers, but none of them refered to VPN capabilities. There were also some incompatability issues noted for connection to nonpublic static IP addresses that resided behinda public dynamic IP address. (LAN nodes behind a firewall or router)

As far as cost, they ranged from free (very limit service) to $75/ month depending on what services are required.

If I remember right, Comcast recently merged with AT&T. If this is the case, a static IP address may be available. This is looking to be your easiest solution for configuring a VPN.

Sorry I couldn't be more help. Good luck.