[pptp-server] can ping but not do much more

[Steve Sarette]

Hi,

I'm trying to get a very simple pptp client setup going in order to read 
email and do web browsing behind my employer's Win2000-based firewall. 
I've managed to get everything working so that pptp connects and 
authenticates.  I can also ping the machines behind the firewall, 
sometimes do DNS lookups (at least they work with ping) and so forth.

Unfortunately when I attempt to do much more than ping my connections 
hang.  For example, netscape mail can successfully authenticate to the 
IMAP server (exchange server, actually), determine the number of message 
headers to download, starts to download the first message header, and 
then nothing.  The same sort of thing happens when trying to connect to 
a web server.  The DNS lookup seems to go ok, but when netscape tries to 
actually load the page, it hangs indefinately.  This is true of both 
communicator 4.7x and the latest beta of communicator 6.0.

Similar problems happen with other tcp activities such as attempting to 
do source tree checkouts.  Oddly, when I try to do a checkout, the tool 
(perforce) complains that it cannot find the source server (unknown 
host) but ping can find it without any problems.  (btw, all of these 
things work when I take my laptop to work and use it there without pptp).

I'm not sure if this is some kind of a routing problem or if this is 
some kind of an incompatibility with my employer's all Windows-based 
network.

/var/log/messages contains no errors of interest.  Is there another log 
file I could look at for hints?

I'm using a stock Redhat 6.2 system on a DSL connection.  At the moment, 
I'm using the default ipchains ruleset in an attempt to eliminate any 
firewall issues.  My system has a static ip so no masquerading should be 
required.  (And yes I intend to put my firewall back together as soon as 
I've demonstrated to myself basic connection functionality).

As I'm fresh out of ideas, I'm hoping someone on this list might be able 
to give me some ideas as to what I could try next. Any thoughts would be 
greatly appreciated.

I admit to being a bit clueless when it comes to ppp, routing, and so 
forth.  Yet I'm so close....

- Steve