Docuemtation of the NTP Client Server setup for Debian 11 "bullseye"
sudo apt update && apt upgrade --show-upgraded
sudo apt install ntp
sudo ufw allow from any proto udp to any port 123
sudo systemctl status ntp
sudo apt install ntpdate ntp
Add server your.ip.addr.ess prefer iburst
sudo vi /etc/ntpsec/ntp.conf
sudo systemctl restart ntp && systemctl status ntp && ntpq -p