Configuring the Network Time Protocol (NTP)

NTP sample scenarios

This first scenario would be used when configuring a single host to use NTP. The host seattle.your_company.com is expected to run as a stratum 2 server because it is configured to get the time from two time servers with radio clocks, ntp1.ossi.com and ntp.olivetti.com. The ntpd daemon stores the frequency error of the clock on seattle.your_company.com in /etc/driftfile. This is a good example to use if you just want to get ntpd up and running quickly. Note that it can take a day or two for a host to synchronize with a time server.

Here is the ntp.conf file for seattle.your_company.com:

# # Peer configuration for 10.0.246.11 (seattle.your_company.com) # peer 192.240.4.1 # ntp1.ossi.com peer 129.189.134.6 # ntp.olivetti.com

driftfile /etc/driftfile

This next scenario is the complete configuration for your_company.com. The configuration files here configure your_company.com to match the topology discussed in ``NTP guidelines''. All hosts can be configured dynamically with ntpd. There are no restrictions on which hosts can be designated as time servers in a given host's configuration file.

Here is the ntp.conf file for acapulco:

# # Peer configuration file for 10.0.246.16 (acapulco.your_company.com) # peer 128.115.14.97 # clock.llnl.gov peer 16.1.0.22 # clepsydra.dec.com peer seattle.your_company.com peer moscow.your_company.com

broadcast 10.0.246.255

driftfile /etc/ntp.drift resolver /etc/ntpres keys /etc/ntp.keys requestkey 65534 controlkey 65535

Here is the ntp.keys file for acapulco:

   2313      M    APassword
   65534     M    NoSecret
   65535     M    BadKey

Here is the ntp.conf file for seattle:

# # Peer configuration for seattle (10.0.246.11) # peer 129.189.134.6 # ntp.olivetti.com peer 192.240.4.1 # ntp1.ossi.com peer acapulco peer moscow

broadcast 10.0.246.255

driftfile /etc/ntp.drift resolver /etc/ntpres keys /etc/ntp.keys requestkey 65534 controlkey 65535

Here is the ntp.keys file for seattle:

   2313      M    APassword
   65534     M    NoSecret
   65535     M    BadKey

Here is the ntp.conf file for moscow:

# # Peer configuration file for 10.0.246.7 # moscow.your_company.com # peer 130.43.2.2 # apple.com peer 192.52.195.10 # norad.arc.nasa.gov peer seattle.your_company.com peer acapulco.your_company.com

broadcast 10.0.246.255

driftfile /etc/ntp.drift resolver /etc/ntpres keys /etc/ntp.keys requestkey 65534 controlkey 65535

Here is the ntp.keys file for moscow:

   2313      M    APassword
   65534     M    NoSecret
   65535     M    BadKey

Here is the ntp.conf file for chicago:

   # Peer configuration used by all stratum 3
   #      servers at your_company.com
   #
   broadcastclient  yes
   broadcastdelay   0.0500
   driftfile        /etc/ntp.drift
   resolver         /etc/ntpres
   keys             /etc/ntp.keys
   requestkey  65534
   controlkey  65535

Here is the ntp.keys file for chicago:

   2313      M    APassword
   65534     M    NoSecret
   65535     M    BadKey