I'm trying to set up a site to site vpn from a remote office to a central office with two Cisco 2811 routers. In the remote office there is a non-Cisco cable modem and router (owned by an ISP- Public IP 188.8.131.52 - not real)
The central router is working ok and have other vpn tunnel active.
The router owned by the ISP has the ports redirected to Cisco 2811 router (10.100.100.20 )(UDP 500, TCP 1723, TCP 47, TCP 50, TCP 51).
Tunnel is up, but line protocol is down and I can't make it work.
Configuration is attached.
thanks for any help