Fast VPN (Virtual private network) connections for Mac OS X

Access to College resources from outside (its firewall) may require a VPN connection (not all resources need this, Exchange email and this Wiki are two examples). The normal VPN uses a PPTP connection, which due to a complex series of factors, may perform very poorly for access via a Mac and an external ISP. The following procedure may provide much faster access, particularly for large file transfers.

If you have previously installed an older version of TunnelBlick, uninstall here.
Install TunnelBlick
You can then download a configuration file from here. This will of itself require a VPN connection and you can use the one provided with the OS X system for this part.
Create an empty un-named folder and put the downloaded configuration file into it.
Now rename the folder to ic.tblk. The folder icon will change to a file icon.
Double-click the icon and the VPN connection config will be imported.
Finally, start Tunnelblick itself (from the icon at the very top right of the screen, or the application itself) and click the connect button. At this stage you will be prompted for your IC login and password.
You can also configure it to start when the computer is rebooted. It will also re-establish the connection if the computer is awoken from sleep (which did not happen with the default VPN client).
You should notice that e.g. file transfers may proceed up to six times faster then using the standard VPN connection.
You may also wish to run a comprehensive test of your network. Save the result as eg http://n1.netalyzr.icsi.berkeley.edu/summary/id=43ca253f-25840-203ecd0c-6ce8-4349-b092

Password Changes

Periodically, all users have to change their password. Since TunnelBlick caches this password, it has to be reset to function. Proceed as follows

Go to VPN details (from the icon in the top rhs)
Select configurations/ic/advanced/VPN Credentials/add credential (you give it the name XXX)
Tick all configurations use XXX
Click connect. This will then prompt for your new account/password.
Repeat every time your password has to change.

CAUTION. This is currently an experimental service. At this stage, other services that need VPN, such as e.g. SciFinder or Scientific Journals, are not yet included in the IP address ranges supported.