[pptp-server] Linux PoPToP 2.4 with LAN Internet connection.

[James Cameron]

While it probably doesn't relate to the thread directly, I have been
testing the new release of the PPTP Client on Linux and found that I can
cause the 'no GRE from server' symptom if I accidentally start the pppd
in such a way that it sends diagnostic messages through the GRE pipe. 
The pppd logging file descriptor was attached to the psuedo-tty that was
attached to the GRE encapsulator.

Indicator 1: if you have considerably more GRE packets sent by the
client than there are LCP packets logged by the client.

Indicator 2: examining GRE packets using tcpdump -X shows they contain
text messages that pppd would normally emit.

-- 
James Cameron