====== NTP server ======

====== Debian ======

OS: Debian 11 (testing)\\
===== NTP server =====

<code bash>
apt-get install ntp
sntp --version
vi /etc/ntp.conf</code>
choose a pool close : https://support.ntp.org/bin/view/Servers/NTPPoolServers
<code perl>
server 0.ch.pool.ntp.org
server 1.ch.pool.ntp.org
server 2.ch.pool.ntp.org
server 3.ch.pool.ntp.org
</code>
<code bash> vi/etc/ntpsec/ntp.conf</code>
<code perl>
# Comment this out if you have a refclock and want it to be able to discipline
# the clock by itself (e.g. if the system is not connected to the network).
#tos minclock 4 minsane 3</code>
<code bash>systemctl restart ntp
systemctl status ntp</code>
==== Ubuntu ====
<code perl>
...kernel reports TIME_ERROR: 0x2041: Clock Unsynchronized</code>
<code bash> ufw allow from any to any port 123 proto udp</code>
==== Debian ====
<code bash> apt install -y firewalld
firewall-cmd --add-service={ssh,ntp} --permanent
firewall-cmd --reload
</code>

==== Clients ====
=== Quick check ===

<code bash> ntpdate ntp.fortier-family.com</code>

=== More ===
-> [[os:linux:systemd:ntp_client|NTP]]


====== Reference ======

  * https://help.ui.com/hc/en-us/articles/220066768-UniFi-Network-How-to-Install-and-Update-via-APT-on-Debian-or-Ubuntu
  * https://community.ui.com/questions/Java-Home-Directory-Fail-Issue-on-Ubuntu-RESOLVED/1faea5fd-6eda-4be9-a12f-676ef6be2529
  * https://community.ui.com/questions/UniFi-Installation-Scripts-or-UniFi-Easy-Update-Script-or-UniFi-Lets-Encrypt-or-UniFi-Easy-Encrypt-/ccbc7530-dd61-40a7-82ec-22b17f027776
  * https://vitux.com/how-to-install-ntp-server-and-client-on-ubuntu/
  * https://linuxize.com/post/how-to-set-or-change-timezone-on-ubuntu-20-04/
  * https://davidshomelab.com/unifi-controller-setup-on-ubuntu-20-04lts/