[ previous ] [ next ] [ threads ]
 From:  "Holger Bauer" <Holger dot Bauer at citec dash ag dot de>
 To:  <m0n0wall at lists dot m0n0 dot ch>, "Thomas Siegenthaler" <thosi at thosi dot ch>
 Subject:  AW: [m0n0wall] PPTP issue (again)
 Date:  Sat, 9 Apr 2005 22:12:25 +0200
there only should be a problem, when more than one pc behind nat tries to connect to the SAME
pptp-server in the internet. this is because the gre-protocol can't be devided to the different
clients without looking into the packets content and deciding where to redirect the traffic by the
included session ids. however, it should be able to connect to different server in the internet as
the decision can be made because of the source ip the packets return. this usually works. at my
office we do a lot of remoteadministration and unless not more than 1 client wants to connect to the
same server it works great.
which version are you running? latest version I tried was 1.2b3 though.
you can look here to undesrtand the problems with the greprotocol behind nat:
Holger Bauer

-----Ursprüngliche Nachricht-----
Von: Thomas Siegenthaler [mailto:thosi at thosi dot ch]
Gesendet: Samstag, 9. April 2005 13:26
An: m0n0wall at lists dot m0n0 dot ch
Betreff: [m0n0wall] PPTP issue (again)

I have three computers in my LAN. Two are running Win2k and one is running WinXP. 

Now, I can connect to a PPTP server in the internet from one of my three pcs in my LAN. As soon as I
established a connection, the other two pcs are not able to connect to ANY PPTP SERVER trough the
internet. But this pc, which I used to establish the first connection (since m0n0wall started) can
still connect to any other server. 
After I reset the NAT state table, I can connect from another PC to the PPTP server. But after this
connect, the same problem occurs as before.
Anyone an idea how to solve this problem ? When I have a look to my sniffer running on the client
machine, it seems like the pptp server sends packets to the client, but these packets never reach
the client.
Please see the attachment. I added a sniffer export. 

Virus checked by G DATA AntiVirusKit