For Christmas my MacBook Pro hard drive decided to die at the ripe old age of 6 months. Go Hitachi!

I restored from a Time Machine backup and installed the full 10.5.6 update.  After rebooting the Cisco VPN kernel module would load, attach to the VMware interfaces and immediately trigger a kernel panic and halt the machine after attaching to en0, the onboard ethernet.

I'm fairly positive that no one at Cisco works full-time on the ipsec VPN client anymore given that it never works with a new release of OS X and seems to stop working on alternating dot-release updates.  Cisco isn't biased though, the ipsec client still doesn't work right on 32-bit Vista (hey, Vista is only two years old, these things take time!), and there is not, nor will there ever be, an ipsec client for 64-bit versions of Windows.

The latest release of the VPN client for OS X is 4.9.01 (0100), which was released over a year ago on December 6, 2007.  Cisco's commitment to the product is evident with the release notes for their "latest" version, which is still listed as 4.9.00 (0050).  While this is a bit tongue in cheek, I do think that Cisco's ipsec vpn client is a dead product. They're pushing the SSL/TLS AnyConnect VPN client hard, and AnyConnect shows signs of being an actively mantined product. It also supports x64 versions of Windows.

Manually removing the VPN client

1. Reboot into single user mode by holding command-S while the computer boots
2. Remount the / filesystem as read-write (it's read-only by default)

   /sbin/mount -uw /

3. Run the uninstaller:

   /usr/local/bin/vpn_uninstall

At this point things will either work, or you'll receive an error saying that you need to be the super user (root). That's odd considering you ARE root.

The problem is in these two lines:

ID="/usr/bin/id"
WHOAMI=`$ID|sed -e 's/(.*//'`

When you're in single-user mode the id command fails, returning "Bus error" instead of a line like

uid=501(cfg) gid=20(staff) groups=20(staff),98(_lpadmin),81(_appserveradm),79(_appserverusr),80(admin)

You'll need to edit the vpn_uninstall script by hand and fake the check.  Use nano or your preferred editor to edit the file.

nano /usr/local/bin/vpn_uninstall

Add a new line right after WHOAMI=`$ID|sed -e 's/(.*//'`:

WHOAMI="uid=0"

The file should now look like:

ID="/usr/bin/id"
WHOAMI=`$ID|sed -e 's/(.*//'`
WHOAMI="uid=0"

Save the file (ctrl+o, enter, ctrl+x, enter) and re-run /usr/local/bin/vpn_uninstall.  At this point it should uninstall successfully and you can type reboot to restart sans-vpn client.