Flush DNS

Chrome:

go to: chrome://net-internals/#dns and click "Clear host cache"

Mac OS:

sudo dscacheutil -flushcache; \
sudo killall -HUP mDNSResponder

Windows:

ipconfig /flushdns

Linux:

systemd:

sudo systemd-resolve --flush-caches

NSCD:

sudo systemctl restart nscd

dnsmasq:

sudo systemctl restart dnsmasq

named:

sudo systemctl restart named