Flushing the DNS in Ubuntu 16.04

flush-dns.sh

#!/bin/bash

# NB: First install nscd with sudo apt-get install nscd

# run this command to flush dns cache:
sudo /etc/init.d/dns-clean restart
# or use:
sudo /etc/init.d/networking force-reload
# Flush nscd dns cache:
sudo /etc/init.d/nscd restart
# If you wanted to refresh your settings you could disable and then run
sudo service network-manager restart

echo "DNS Flushed!";

# Output:

# craig@laptop:~$ sh Desktop/Scripts/flush-dns.sh 
# [sudo] password for craig: 
# [ ok ] Reloading networking configuration (via systemctl): networking.service.
# [ ok ] Restarting nscd (via systemctl): nscd.service.
# DNS Flushed!

All of these give me command not found.

It looks like you do not have nscd installed you can install it by doing sudo apt-get install nscd on Ubuntu

Correct, you must install nscd first. Added this and example output to the gist.

if you use systemd-resolve in 16.04

sudo systemd-resolve --flush-caches

when i run: sudo systemd-resolve --flush-caches , I get a error: sudo systemd-resolve --flush-caches in Ubuntu 16.04.
Please help me.

Couldn't get sudo systemd-resolve --flush-caches to work on Ubuntu 16.04 as well.

Couldn't get sudo systemd-resolve --flush-caches to work on Ubuntu 16.04 as well.

systemd-resolved doesn't seem to be an active service by default in Ubuntu 16.04.

You have to start it first with sudo systemctl start system-resolved

I had ERR_NAME_NOT_RESOLVED Error in Chrome. sudo /etc/init.d/dns-clean restart helped. Thanks