PPTP and NAT (but it isn't the usual question)

[mmez]

Hi all,
at home I've a Cisco 827-4V router with 12.2(8)T4 IOS version. It's connected to an ADSL line and my ISP assigns to it a dynamic address.
As I have three PC which need to connect to the Internet, I configured the router to perform overloaded NAT.
This way, PPTP connections to my office VPN server, do not work.
If I configure a static nat between the inside global address and one of the inside local addresses, connections work perfectly.
But there are two problems with this configuration:
1) The inside global address is dynamic: so everytime I've to change the ip nat inside source static statement.
2) Just one PC at a time (the static natted one) can establish a PPTP connection.
Is there any solution to allow all my three PC to connect to the PPTP VPN server simultaneously?

Thx.

 

[ShaunG]

My understanding of VPN through NAT is that it requires a one to one translation, so it won't work through overloading and you won't be able to use more then one computer at a time.

The only solution I know of is to get some static IP's from your ISP. My ISP gives me a block of 8 addresses for 20 a month.