Reset DNS cache en OS X

MacOS X Yosemite 10.10.4

sudo killall -HUP mDNSResponder

MacOS X Yosemite 10.10.3 Through v10.10.3

sudo discoveryutil mdnsflushcache

MacOS X Mavericks, Mountain y Lion.

sudo killall -HUP mDNSResponder

MacOS X v10.6

sudo dscacheutil -flushcache