#set ntpd use loacl time, u16

sudo apt install ntp

sudo gedit /etc/ntp.conf

#server 0.north-america.pool.ntp.org

#server 1.au.pool.ntp.org

#server 2.au.pool.ntp.org

#server 3.au.pool.ntp.org

#pool ntp.ubuntu.com

#broadcast 172.255.255.255

#caution / important !!

#add

#iburst prefer

#ntpd run and work right away/immidiately without sync/ 5 minutes wait

#

#avoiding 

# no server suitable for synchronization found

//---

/etc/init.d/ntp start

/etc/init.d/ntp stop

ntpstat

watch ntpq -p

netstat -ln | grep 123

sudo nmap -sT -sU -p 123 localhost

sudo ufw allow 123/tcp

sudo ufw allow 123

sudo ufw allow from any to any port 123 proto udp