How to clear the local DNS cache….
OSX 10.10.4
QUOTE:
sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder;say cache flushed
OSX 10.10 (10.10, 10.10.1, 10.10.2, 10.10.3)
QUOTE:
sudo discoveryutil udnsflushcaches
參考: http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/