OSX DNS issues

Is your mac behaving oddly with regards to DNS in that its not honoring the DNS server? I found out the hard way that apple, with its mDNSResponder service, broke tried and tested DNS on OSX. There are plenty of places on the net you can find this mentioned and its surprising and frustrating that Apple hasnt fixed it yet. Anyway, if DNS is behaving oddly on your mac, start with:

sudo killall mDNSResponder

It will restart itself and refresh DNS.