Flowpoint and PPTP/VPN

[Jeremy Jones]

One of my clients has a flowpoint dsl router with can handle gre (protocol
47).  The tcp port needed is 1723.


-----Original Message-----
From: Jon Carnes [mailto:jonc at HAHT.COM]
Sent: Thursday, January 20, 2000 5:45 AM
To: VPN at SECURITYFOCUS.COM
Subject: Re: Flowpoint and PPTP/VPN


Microsoft's PPTP uses two ports - I believe they are 1027 and 47.  The
initial connection is made on port 1027, and then data is passed on port 47.
It's been a long time since I read the specs, but they are up in Microsoft's
Knowledge base.

If your router (the flowpoint box) is using masquerading then you will have
problems using MS PPTP.  Most masquerading firewall/routers now have patches
to allow PPTP to pass through them.  We use a Linux box as our
firewall/router and we had to apply a patch to our kernel so that the GRE
packets (port 47) would be redirected to the proper box inside our firewall.

Also, some ISP's do not pass GRE packets.  You may want to confirm with them
that will allow PPTP to travel into and across their net.

Also, check in with MS's knowledge base.  They have  lot of info logged up
their on getting your PPTP to work.

Jon Carnes
MIS - HAHT Software
----- Original Message -----
From: Frank R. Boecherer
To: VPN at SECURITYFOCUS.COM
Sent: Tuesday, January 18, 2000 10:12 PM
Subject: Flowpoint and PPTP/VPN


If you have (or not) experience with Flowpoint routers, maybe you can offer
some tips...

We are trying to setup remote access to our NT with one end of the
connection being a remote computer connected to the Internet via cable modem
and using Microsoft's PPTP VPN and the other end being the main office
server with cable modem and a Flowpoint ethernet to ethernet router.

Everything seems to be going OK after clickin the VPN dialup icon, but after
the box that says "Verifying user name and password" comes up, the
connection times out and we get an "Error 650: The computer you're dialing
in to does not respond to a network request.  Check your server type setting
in the properties of the connection.  If this problem persists, check with
your network administrator."

We have filtering turned off, I believe, on the server, but I read somewhere
that we may need to turn on GRE protocol 47 in the router to allow the
passing of certain packets or header data.  Can anyone explain what GRE is
and maybe how to enable it on the Flowpoint and if that is the problem we
might be experiencing?

Thanks

Frank

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