Un serveur NTP est un serveur de "temps" utilisant le protocol NTP permettant à toutes les stations d'un réseau local de se synchroniser afin d'avoir la même heure ...

Distribution : Ubuntu Server 8.04 r2

apt-get install ntp

Ouverture du port 123

iptables -A INPUT -p udp --dport 123 -j ACCEPT

Exemple de fichier /etc/ntp.conf

# /etc/ntp.conf, configuration for ntpd
logfile /var/log/ntpd
driftfile /var/lib/ntp/ntp.drift
statsdir /var/log/ntpstats/

statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable


# You do need to talk to an NTP server or two (or three).
#server ntp.your-provider.example

# pool.ntp.org maps to more than 300 low-stratum NTP servers.
# Your server will pick a different set every time it starts up.
#  *** Please consider joining the pool! ***
#  *** <http://www.pool.ntp.org/join.html> ***

server ntp.univ-lyon1.fr
server ntp.imag.fr
server ntp.uvsq.fr
server ntp.laas.fr
server ntp.unilim.fr
server 127.127.1.0
fudge 127.127.0.0 stratum 10

# By default, exchange time with everybody, but don't allow configuration.
# See /usr/share/doc/ntp-doc/html/accopt.html for details.
restrict default kod notrap nomodify nopeer noquery
restrict 127.0.0.1 nomodify
restrict 10.0.0.0 mask 255.255.255.0 nomodify notrap

Vérifications du fonctionnement du service NTP

ntpq -p

Vous devez obtenir quelque chose comme ceci :

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 dns.univ-lyon1. 195.220.94.163   2 u    8   64    1   62.282   24.999   0.001
 imag.imag.fr    192.93.2.20      2 u    7   64    1   65.826   24.263   0.001
 soleil.uvsq.fr  195.83.222.27    2 u    6   64    1   56.883   23.244   0.001
 ntp1.laas.fr    138.96.64.10     3 u    5   64    1   86.354   21.182   0.001
 ntp.unilim.fr   195.220.94.163   2 u    4   64    1   65.269   21.632   0.001
 LOCAL(0)        .LOCL.           5 l    3   64    1    0.000    0.000   0.001