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New Member

PPTP over 677 DSL router

I am trying to setup a VPN between two offices that are both connected to the same ISP, using a 677 DSL router in routing mode.

When trying to connect the VPN client to the server over the internal LAN all goes well, but when I go over the internet the client gets stuck in the login process.

Assume the problem lies in the fact that the 677 does not allow for a PPTP tunnel to be created.

On the 677 I have port 1723 TCP and UDP mapped to the VPN server.

Any suggestion on how to configure the 677 in such a way that is allows for an incoming PPTP tunnel would be highly appreciated.

New Member

Re: PPTP over 677 DSL router


You can’t use NAT overload to connect and you need to open 1723 tcp and IP protocol 47/GRE.

New Member

Re: PPTP over 677 DSL router

Using CBOS, how do I open the 47/GRE on the 677 router?

New Member

Re: PPTP over 677 DSL router

Please provide information on allowing PPTP thru the Cisco 677 if you get it to work or receive an answer on what the configuration should look like.\\\kind regards


New Member

Re: PPTP over 677 DSL router

The solution is quite simple:

Through telnet go to enabled mode and add following mapping:

set nat entry add 0 47

write + reboot, and off you go!


PS: The is the IP address of the NIC connected to eth-0

New Member

Re: PPTP over 677 DSL router

actually your static NAT entry would be:

set nat entry add 1723 1723 udp

set nat entry add 1723 1723 tcp

This is assuming that your internal machine is set to the ip address of

The is best used if you have a dynamic external ip address otherwise if you are using static IP and NAT then the would be replaced with your outside nat IP address.