Mac OS X v10.6
sudo dscacheutil -flushcache
OS X Mountain Lion または Lion
sudo killall -HUP mDNSResponder
OS X Yosemite
sudo discoveryutil mdnsflushcache sudo discoveryutil udnsflushcaches
http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/ https://support.apple.com/ja-jp/HT202516
