[pptp-server] MsExhange through MASQ and PPTP

[Cowles, Steve]

I use MS Outlook (configured with the Exchange Server Service, not POP3)
across my PPTP connection without any problems. 

My network topology is identical to yours...
1) Linux based firewall masqing my internal LAN through DSL.
2) MS Exchange server sitting on private network. i.e. 192.168.x.x
3) PopTop server for remote PPTP connections.

The only port/protocols I open up on my fireall are Protocol 47 and Port
1723. I do not use port forwarding (at least for Outlook access to my
Exchange server)

There are many ways a masq'd Exchange server can be accessed from remote
sites.
1) Exchange WEB interface. Requires forwarding port 80.
2) POP3 - requires forwarding port 110
3) MS Exchange Server Service. requires PPTP VPN along with an active WINS
server.

There are probably a few others, but the above are the most common.

When I create a VPN into my poptop system from a remote site, I can use all
applications just as if my Laptop (NT4.0 sp6a) was connected directly to my
LAN. Applications such as... Exchange Admin, WINS admin, DHCP admin, Event
viewer, SQL, Server Admin and MS Domain authentication work perfectly across
the VPN. Even Network Neighborhood looks identical to what users are seeing
on the LAN.

Based on your post, I can offer a couple of ideas: 
1) In your test environment... are you using a WINS server? 
2) In your /etc/ppp/options file... are you specifying the ms-wins option?

If your not able to use a WINS server in your test environment, then you
will probably need to create a LMHOSTS file that contains the definition
(Netbios names) for your Exchange server.

Steve Cowles