Mac El Capitan 10.11.1
$ sudo killall –HUP mDNSResponder;say flushed
Mac Yosemite 10.10.4+
$ sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder;say cache flushed
Mac Yosemite 10.10.3-
$ sudo discoveryutil mdnsflushcache;sudo discoveryutil udnsflushcaches;say flushed
Ubuntu:
Note: Ubuntu doesn't cache DNS by default unless you install a DNS cache service manually.
$ sudo /etc/init.d/dns-clean restart
Windows:
Right-click Command Prompt and select Run as Administrator.
Run the following command: ipconfig /flushdns
Important:
Don't forget to change your host file's IP to 10.57.225.54 for halprdgit01.hq.halw.com if you use a Mac or Linux machine and hard-coded the IP into the host file.