Re: SBS VPN Error: 781

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From: Harlequin (michael.mason_at_arraspeople.co.uk)
Date: 11/30/04 

Date: Tue, 30 Nov 2004 01:58:27 -0000

Thanks very much Chris. This helps clear things up a little for me.

In my specific scenario I am using SBS as the VPN endpoint and Windows XP as
the client. The client simply downloads and executes the connection set-up
wizard so I am unsure which ports or protocols to set-up on the modem.

Given the above, what I have done is tell the modem to forward both ports
500 and 1701. However, it does not allow me to specify protocols and I've
never even come across protocol "GRE". So you can see my dilemma now I hope.

Error 781 in the MS KB indicates that I need a security certificate (which I
have installed). That said, I now get error 800 which if I am interpreting
the KB articles correctly would indicate that the modem is either not
forwarding the correct ports or it is forwarding the correct ports but using
the incorrect protocols.

I checked on the server's "Routing and remote access" application and
checked the ports available and their settings and it appears that both L2TP
& PPTP are catered for.

Does the above help...? I hope it does and I'm grateful for your time on
this. 

-- 
-----------------------------
 Michael Mason
 Arras People
 www.arraspeople.co.uk
-----------------------------
"Chris Puckett [MSFT]" <cpuckett@online.microsoft.com> wrote in message 
news:gelgFNn1EHA.3980@cpmsftngxa10.phx.gbl...
> Think of the term VPN as a generic term.
>
> There are 2 underlying protocols that can be used to create a VPN.  Those 
> 2
> protocols are PPTP and L2TP.
> You can use one or the other to create a VPN connection.  In either case,
> the client and the server must be using the same protocol in order for the
> VPN to be established. The VPN protocol you are using to create your VPN
> connection determines the ports you must open/forward to the server.
>
> PPTP uses TCP port 1723 and the GRE protocol.
>
> L2TP uses UDP port 500 and UDP port 1701.
>
> Chris Puckett, MCSE
> Microsoft Small Business Server Support
>
>
> This posting is provided "AS IS" with no warranties, and confers no 
> rights.
> --------------------
>

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