Important note about software versions
We strongly recommend you do not automatically update Tunnelblick when prompted to, as new releases often break things. Instead check this web page first to find out if we have tested the new version and only upgrade to versions we have mentioned here that we have tested.
Which version to install depends on which version of MacOS you have. For 10.7.5 and up we currently recommend the 3.6.10 stable release which may be downloaded from https://tunnelblick.net/downloads.html . Although we cannot test every version this one has been seen to work on OSX 10.11 for us. Please note we do not recommend the 3.5.5 or 3.6.2 stable releases which we have had reports of problems with. For older Macs version 3.5.11 should work.
If you have difficulty with version 3.6.8 then what to try depends on the version of OSX you have. If you have OSX 10.7 or above try the latest beta release from https://tunnelblick.net/downloads.html . For older versions of OSX there is no readily available alternative.
After installing tunnelblick, download the config file. The configuration file is compressed, so double-click it to expand it: you should then get a file 'Chemistry.tblk'. ('Chemistry.tblk' will not run from the Downloads folder. Copy to the Desktop). Double-click 'Chemistry.tblk' to install the configuration.
Select 'Connect Chemistry' from the TunnelBlick icon. The credentials you should use are your ChemNet credentials. These can be collected from https://apps.ch.cam.ac.uk/ssms/collectchemnet and it is OK to tell Tunnelblick to save them. Please note that the ChemNet username is your CRSID followed by @ch.cam.ac.uk , not @cam.ac.uk .