OS X: How to reset the DNS cache - Apple Supporthttp://support.apple.com/en-us/ht5343
Flusher les caches DNS sous Mac OS :
OS X Yosemite (10.10.4 - ) : sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder
OS X Yosemite (10.10.1 - 10.10.3) : sudo discoveryutil udnsflushcaches
OS X Mountain Lion / Lion : sudo killall -HUP mDNSResponder
Mac OS X v10.6 : sudo dscacheutil -flushcache