Fedora Core 3 + PPTP - NAT: Problems with multiple clients

Michael Sonntag sonntag at fim.uni-linz.ac.at
Thu Apr 14 21:58:47 CEST 2005

I have a firewall which does NAT of outgoing connections. Several clients
behind this box must connect to the same external PPTP server. This did work
fine on a 2.4.27 kernel.

However, with the newest version of the PPTP conntrack/nat helper (from SVN,
Revision 3839) and Fedora Core 3 (2.6.10), this does no longer work (both
clients and server are unchanged, only the firewall is replaced). It applies
cleanly and I can connect to an external PPTP server from a single client:
everything works fine. But as soon as a second client behind the firewall
tries to connect to this server, problems occur. Either the connection does
not get established (most cases), or the first connection is broken
(rarely); completely working: never. It seems, that some packets get mixed
up between those two connections.

Is there any workaround for this or how to help the developers in resolving
the problem? I have enabled all the debugging (printk), but the resulting
log doesn't help (at least me).


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