Patch flushDNSCache
function located in /Applications/Tunnelblick.app/Contents/Resources/client.up.tunnelblick.sh
with following code inside case
statement:
10.10 )
if [ -x /usr/sbin/discoveryutil ] ; then
/usr/sbin/discoveryutil mdnsflushcache
logMessage "Flushed the DNS Cache"
else
logMessage "/usr/sbin/discoveryutil not present. Not flushing the DNS cache"
fi