PPTP - Whats going on with EFW and PPTP? Possible solution...

[Guest]

[effgee]

Here's the scenario.

I have a PPTP server  running on a linux machine Centos 5. POPTOP
I have GRE (PPTP Passthru) enabled on my router as well as the PPTP ports TCP/1723.
With my Firewall / Router device, everything works just peachy.

Fast forward....
Installed EFW.. configured the same ports and GRE pass through.
Gets stuck at username and password.
Check my logs, see this : CTRL: PTY read or GRE write failed (pty,gre)=(6,7)
Lots of Google searching. Come across these two links.

poptop.sourceforge.net/dox/qna.html
which leads to...

pptpclient.sourceforge.net/howto-diagnosis.phtml#read_eproto
I kill pptpd, modprobe ip_gre , start pptpd..
And lo and behold I connect with the native windows PPTP client.

If I kill pptpd and restart it, it once again fails to connect in the same place.
I have to
kill pptpd,
rmmod ip_gre ,
modprobe ip_gre,
and start pptpd again to be able to connect.

WHAT IS GOING ON!?