[Macworld]

Post your comments for Fix an error 51 with the Cisco VPN Client here

[andretoulouse]

I have a hardware vpn now, and when I was using the built in VPN I was also using Tiger, so I appologize if this information is outdated.
When I was using the built in VPN client I was able to resolve the iChat connection issue by doing two things. The first was opening up the VPN settings and unchecking the "Send all traffic over VPN connection". The second was setting the order of the connections so that the VPN connection was lower in the list than airport and ethernet. On Tiger the second was found in the Internet Connect application, and I believe it's been moved to the Network settings, Set Service Order option under the action menu (the gear icon) at the bottom of the list of connections.

[chrissnv]

Another Tool that works really well with the Cisco VPN Dialer is Shimo. Since I use Shimo I had no more problems with the VPN Subsystem.

[folklore]

Seconded. I've been using Shimo for awhile now and agree - it's much easier to use and solves the occasional problem I had with the actual Cisco client.

[cobra_libre]

Interesting. I thought that Shimo merely acted as a frontend to the Cisco VPN Subsystem; while it provides a great UI, it hasn't stopped the occasional errors as described in this article -- at least, not for me. I'll have to look into how I have it configured.
BTW, it's a good idea to define an alias for this command so that you don't need to memorize it or refer back to an article like this when you need it.
For example, you could add the following line to ~/.bash_profile:
alias restart-vpn='sudo SystemStarter restart CiscoVPN'

[opaekaa]

What is Shimo? I've never heard of it.
I find the sudo command also stops a nagging problem where the CISCO VPN simply doesn't connect, and finally comes back with the message 'closed by local client' or something to that effect.
In one case, I had to use the sudo command twice to fix this.
Thanks, Rob. This is really helpful!

[khjalmarj]

I've been using VPNrestart for years (http://www.timdowling.com/blog/2006/03/cisco-vpn-restart.html) to fix this. If I can make this hint into a clickable app, I may use this instead. VPNrestart works every time, though, so perhaps not.
--Keith Johnson

[jHal]

For a few of my Macs, disabling the Firewire port from Networking has solved the error 51 issue. (Mac OS X 10.5 with the Cisco VPN Client 4.9.01 (0100). The only side effect is this will disable ad-hoc networking using Firewire, something which I have never used anyways.
System Preferences > Networking, select the FireWire port and make it inactive by clicking on the gear. Then I click the minus button to remove it from the list.
This was based on someone else's discovery and posting on another site.
I would like to know if these resolves the issues for other users as well.

[Dan Frakes]

opaekaa said:

What is Shimo? I've never heard of it.

http://www.macworld....7/08/shimo.html

Like Rob, I use the Cisco client?via Shimo? specifically to work around this frustrating issue with iChat.

[mpitogo]

I support our VPN in the enterprise and am very familiar with that error. You can update your tip to include a double clickable applet made with apple script. All you need to do is put the below line in script editor and save it as non editable then distribute to users. When run it just asks for admin auth. Sometimes I find even running this doesn't fix the VPN and in those few cases only a reboot will cure it. So far its worked well enough to keep around. Cheers!
do shell script "SystemStarter restart CiscoVPN" with administrator privileges

[tvbarn]

So I had to re-install Leopard the other day and that's when I started getting Error 51.
The bad news - the terminal fix didn't work.
The good news - reinstalling VPNCLient did.

[pdm32]

Cisco has also posted a fix:
http://www.cisco.com...ps2308/productsqandaitem09186a00801c2dbe.shtml

This fix did not work for me, and neither did the Macworld fix, but my Terminal message suggests I am missing a bundle. I will try to re-install the bundle by installing / re-installing the most recent client tomorrow.
The Terminal message I get is:
sudo kextload /System/Library/Extensions/CiscoVPN/CiscoVPN
kextload: /System/Library/Extensions/CiscoVPN/CiscoVPN: no such bundle file exists
can't add kernel extension /System/Library/Extensions/CiscoVPN/CiscoVPN (file access/permissions) (run kextload on this kext with -t for diagnostic output)
Am I guessing correctly that an install of the most recent client should correct this? Or is there also a permissions problem here? I am clearly not a Terminal pro.
Thanks in advance for your thoughts.

[tvbarn]

That's funny - my wife suggests I'm missing a bundle, too, at times.

Anyway, thanks for posting that link. I simply reinstalled VPN Client and was fine.

The whole incident was weird, though.