Resetting the DNS cache on OS XEdit

Sometimes a process will claim that a host is unknown when trying to connect with one process (eg. git push) but others have no trouble doing so (eg. ping). The solution may be to bounce the DNS cache.

Working as of macOS High Sierra:

sudo killall -HUP mDNSResponder
sudo killall mDNSResponderHelper
sudo dscacheutil -flushcache

Source

Older notes

The finessed approach

$ sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
$ sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Verified to work on OS X 10.11.2 El Capitan.

Source

Via brute force

$ sudo killall -HUP mDNSResponder

Source

See also