[NCLUG] Please Help

[Michael Dwyer]

Muhammad Bhatti wrote:
> But I am getting following error when want to connect
> from windows 2000 machine to my linux box running
> poptop version "pptpd-1.0.1".
> 
> What could be the reason for that. I am already late
> please help.
> 
> Apr 29 10:28:03 itdiv pptpd[14007]: GRE: Discarding
> duplicate packet
> Apr 29 10:28:34 itdiv pptpd[14007]: GRE:
> read(fd=4,buffer=804da20,len=8196) from PTY failed:
> status = -1 error = Input/output error
> Apr 29 10:28:34 itdiv pptpd[14007]: CTRL: PTY read or
> GRE write failed (pty,gre)=(4,5)

> Also if u could help or tell me the sites that
> explains about all the possibilities of P.C based VPN
> solutions constraints on different tunnel protocols
> 
> Like IPSec is not supported by Windows 9x. etc.

I was never able to get PPTP to work for me.  This was almost two years
ago, so things might be better by now, but I digress...  The quick thing
I would mention is to make sure you have GRE supported in your kernel. 
The negotiation is over TCP, but then switches to GRE -- and if GRE
isn't routable on your network, that might cause a problem...

Finally, for what it is worth, I found that for connecting two networks
together, linux boxes running CIPE worked beautifully!  It wasn't useful
for single PCs to connect, but it was ideal for connecting remote
offices together.  Our final solution was to use CIPE to link the
offices, then use an NT server to provide the PPTP connections for users
at home.