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VPN over GPRS on Mac


We have Intel-based Mac's, running Mac OS X 10.4.6 Tiger.

We have no problems to make a vpn connection over a normal internet connection.

However, when we try to make a vpn connection over GPRS, it's impossible.

Internet over GPRS works fine, but when we start the VPN client (4.9), we receive error 51.

Can this be a bug, or are we doing something wrong?

Please help!

Many thanks in advance!


Re: VPN over GPRS on Mac

Could you provide the full error message which you are getting?


Re: VPN over GPRS on Mac

Have you got nat-tarversal enabled on your PIX? When you are connecting via the GPRS you are possibly hitting a NAT device (NAT breaks IPSec).

On your PIX in config mode enable:

isakmp nat-traversal

Let me know if this helps and pls rate posts!


Re: VPN over GPRS on Mac

Also, forgot to add..

Make sure that on your vpn client you have Transparent Tunneling enabled (Under Transport Tab) + IPSec over UDP (NAT/PAT) ticked.



Re: VPN over GPRS on Mac


thanks for the possible solution, but unfortunately it didn't solved our problem.

Is it even supported, vpn over GPRS on a mac?

I didn't find anything in the release notes.

Is here someone that has managed to get it working?

this is what we do:

We connect the GPRS connection

We start the VPN software,

When this software is starting up, it freezes and we receive the error "System Error: IPC Socket allocation failed with error ffffffff8h"

I know there is a bug, but it was first found in version 4.0 and 4.6, it is related to the microsoft version, and was unreproducable.

In my case, it is mac (intel based), version 4.9, and it happens al the time?

Should I open a TAC case?

Kind regards,


New Member

Re: VPN over GPRS on Mac

I have the same issue. I connect a cell phone to a Mac laptop with a USB cable. I then connect to the internet with no problem. But when I launch the Cicso VPN client, I get the error.

Here's a workaround that works sometimes. If I connect to a wireless network or via ethernet and get a valid IP address, then launch the VPN client, I can then disconnect from that network and connect via the cell phone. The Cisco client works.

But not all the time.

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