Re: Problem makeing a ppp-ssh tunnel.

[Bret Hughes <bhughes@elevating.com>]

On Sun, 2005-03-13 at 10:21, David Ronis wrote:
> Hi,
> 
> I'm trying to use ssh and pppd to set up a ppp tunnel between my
> laptop at home and a machine at work.  Both machines are running a
> 2.6.11 kernel, slackware 10.[01] and have pppd 2.4.3 installed.  I
> more or less followed the instructions in the ppp-ssh howto, which
> essentially runs the following command as root:
> 
> /usr/sbin/pppd ktune noauth updetach passive pty 
> 	"${REMOTE_COMMAND}" ipparam vpn ${CLIENT_IFIPADDR}:${SERVER_IFIPADDR}
> 
> where
> 
> REMOTE_COMMAND=ssh -l ${SERVER_USERNAME} ${SERVER_HOSTNAME}  \
> 	sudo /usr/sbin/pppd ktune noauth nodetach notty proxyarp ipparam vpn
> 
> where ${SERVER_USERNAME} has sudo privilages on ${SERVER_HOSTNAME}.
> 
> and where ${CLIENT_IFIPADDR} is the IP address my laptop has when it's
> connected at work and where ${SERVER_IFIPADDR} is the IP address of
> the server 132.206.205.86 and 132.206.205.91, respectively.
> 
> ifconfig shows:
> 
> ppp0      Link encap:Point-to-Point Protocol  
>           inet addr:132.206.205.86  P-t-P:132.206.205.91  Mask:255.255.255.255
>           UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
>           RX packets:4 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:21 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:3 
>           RX bytes:62 (62.0 b)  TX bytes:4590 (4.4 Kb)
> 
> on the client and
> 
> ppp0      Link encap:Point-to-Point Protocol  
>           inet addr:132.206.205.91  P-t-P:132.206.205.86  Mask:255.255.255.255
>           UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
>           RX packets:4 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:49 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:3 
>           RX bytes:62 (62.0 b)  TX bytes:4302 (4.2 Kb)
> 
> on the server.
> 
> pppd has created route entries:
> 
> 132.206.205.86  0.0.0.0         255.255.255.255 UH        0 0          0 ppp0
> 
> on the server 
> 
> and 
> 132.206.205.91  0.0.0.0         255.255.255.255 UH        0 0          0 ppp0
> 
> on the client
> 
> If I ping 132.206.205.86 from the client I get a response, but if I
> ping the server (132.206.205.91) I get nothing.
> 
> Similarly, pinging the client from the server doesn't get a reply.
> 
> Finally, the connection times out.
> 
> 
> My suspicion is that I'm close, but am making some sort of trivial
> mistake.  Any ideas?
> 

I am certainly no expert but I would next try traceroute
ip_of_remote_end  on bothe ends and try to figure out where the packets
are going.  The route command output is curious it may be valid but I am
used to seeing * instead of 0.0.0.0 for the gateway ip.

Looking at eh transmit and recieve byte counts looks like the packets
are not getting there. I would delete the routes manually and recreate
them if the packets are not getting there.

Bret