VPN and Resolving Issues on OS X

We have a lab which we can access by using a VPN (Cisco ASA and Cisco AnyConnect). This setup has a so-called split DNS configuration, which means that only resources in the lab are accessed through the VPN tunnel. Regular Internet traffic uses my local DSL connection.

At my house I (like most folks) rely on DHCP for providing me with IP address, gateway and DNS servers. My local subnet uses 192.168.10.1 for DNS and 192.168.10.254 is my default gateway. So my clients are in the same subnet as my DNS server (directly-connected).

All these things considered I should be able to browse the Internet while I have a VPN running. Well, that's where you're wrong.

Junos Pulse, Apple iOS, and Split-Tunneling

When you create (SSL)VPN access for you employees, you might enable split-tunneling to save corporate bandwidth. No split-tunneling means that all traffic is forwarded into the VPN tunnel. So if you browse the internet with an active VPN, the traffic goes through the VPN, and accesses the Internet through the corporate Internet connection. This isn't a big problem with a couple of employees, but with hundreds on the road or working from home, this might frustrate the employees in the building.

CiscoVPN Error 51 Annoyance

The CiscoVPN client (v4.9.01.0100) for Apple OSX throws an error every once in a while. Mainly when I just rebooted, or when I was forced to quit some hanging application (which also occurs on Macs). The error is:

Error 51: Unable to communicate with the VPN subsystem

Somehow, the VPN software looses contact with the network adapter (wired AND wireless). After this there are two things you can do;

Reboot
or restart the Cisco VPN Service manually.

The first is kinda obvious (it's almost a MS Windows strategy :)). The second one is done via the Terminal (Finder -> Applications -> Utilities -> Terminal). Just type the following command (followed by your password);

sudo /System/Library/StartupItems/CiscoVPN/CiscoVPN restart

The thing I don't understand is; Why hasn't Cisco incorporated this in the VPN client?

IF (Error 51 == TRUE)
DO CiscoVPN.restart

It seems that this 'bug' is present since the release of the Mac OSX version of the software.

Posted on May 20, 2008 by Willem and filed under Annoying, Apple, Security, Software, Tips'n Tricks and tagged Cisco Error 51 VPN.