[pptp-server] Firewall GRE

[Michael Concannon]

On to the next level...

I am getting the following error(s):
LCP: timeout sending Config-Requests
GRE: read(******) from PTY failed: status -1 error = Input/output error
CTRL: PTY read or GRE write failed (pty,gre)=4,5)

When I try to connect from behind another firewall to my server out on
the internet.

I have opened up my server (too much for the sake of debug) with the
following IPCHAINS rules (this is the target PPTP server as well):
ipchains -A input
ipchains -A output
ipchains -A forward -j ACCEPT
ipchains -A forward -p 47 -j ACCEPT

The forwarding should not be required as this is the same machine that
is running the pptpd server, but I did it anyway.  So, this machine is
wide open.

My first question is could the firewall I am sitting behind (with my 98
client) be blocking the type 47 communication?  My current setup looks
like this:
98 client<--->firewall <---internet---> PPTP/IPCHAINS server

I cannot see why that would be the case...

Some config info:
Server:
linux 2.2.16
pptpd/pppd patched.updated per FAQ
Server is both masquerade box and PPTP server (for now).

Client:
win98 PPTP

*****

I am able to connect in a "loopback" mode from home using this same
client (from behind the PPTP/IPCHAINS server above).

Thoughts?
Thanks again,

/mike