[pptp-server] Weird connection problem

[Nate Carlson]

On Mon, 13 Mar 2000, Andrew McRory wrote:

> 
> Hello,
> 
> I have setup several PoPToP servers and until we tried to put one on a
> cable modem have had great success! I have been through the configuration
> time and time again but am stuck so I'm asking for help...
> 
> We have a server on a cable modem with 2 ethernet cards. eth1 is connected
> directly to the cable modem and for illustrative purposes we'll say it's
> assigned a static IP of 192.168.3.100. the cable modem is behind two
> routers/firewalls and the cable company has assigned an external IP of
> 192.168.1.100 (forget this is not a valid INternet address - it's just an
> example).
> 
> 192.168.1.100 is translated to the actual cable modem IP 192.168.3.100 so
> all connections from the internet make it to the destination. I can SSH
> into ther server and can telnet to port 1723 just fine. The problem starts
> when we try to initiate a connection from the Windows 98 machine we get an
> "error 629 you have been disconnected from the machine you dialed...". My
> Windows machine will connect to other PoPToP servers but not this one.

*massive snip*

According to the above, the cable modem has it's own IP address, and then
NAT translates traffic to your machine. Are you _positive_ that it is
translating & allowing GRE? From what I can tell, it doesn't sound like
the GRE traffic is ever getting to the linux box... I've heard of tons of
problems using cable modems with weird protocols, this could be another
one of those..

-- 
Nate Carlson <natecars at real-time.com>   | Phone : (612)943-8700
http://www.real-time.com                | Fax   : (612)943-8500