[pptp-server] Solved: GRE: Bad checksum from pppd or Windows 720 errors

[Lillian Kulhanek]

We figured out the solution internally.  I was assigning the local and
remote ip addresses in pptpd.conf, and the vpn adapter on the windows client
was configured to have the addresses assigned by the server, which is
supposed to work.  But they weren't being assigned, and Error 720 would pop
up.

When I manually assigned the addresses in the vpn adapter properties,
everything worked, compression, encryption, browsing, life is grand.  I'm
using linux kernel 2.2.17 with pppd 2.3.11 and associated patches/diffs.

Here's the hitch:  For the sake of getting a vpn up, earlier on I installed
a 2.2.16 kernel with pptp and ppp rpms, I was still getting booted off, but
the local and remote addresses were being assigned, according to the logs.
Hmm.  Why then, but not now?

I'm investigating now why the addresses don't get assigned in pptpd.conf,
but if anyone sees something I've missed, I'd be glad to hear it.


-----Original Message-----
From:	Lillian Kulhanek [mailto:Lillian.Kulhanek at energy.on.ca]
Sent:	February 2, 2001 4:02 PM
To:	'pptp-server at lists.schulte.org'
Subject:	GRE: Bad checksum from pppd

Hi all,
So close and yet so far.  PPTP on a Linux box, masqueraded behind a
firewall.  We could establish a connection with a client, but it disconnects
almost immediately, looks like from the peer side.  In our debugging
efforts, we tried to isolate the problem by connecting from a Win98SE
computer within the network directly to the vpn (modems/firewall bypassed).
In this manner, we are able to login, with MSCHAP-v2 peer authentication, as
you'll see in the logs, then the peer disconnects.