This example is intended for systems which use dial-on-demand connections. The normal configuration should be sufficient for mobile and virtual devices which connect intermittently. First, review and confirm that the default settings in the /etc/chrony.conf are similar to the following:

driftfile /var/lib/chrony/drift
commandkey 1
keyfile /etc/chrony.keys

The command key ID is generated at install time and should correspond with the commandkey value in the key file, /etc/chrony.keys.

Using your editor running as root, add the addresses of four NTP servers as follows:

server 0.pool.ntp.org offline
server 1.pool.ntp.org offline
server 2.pool.ntp.org offline
server 3.pool.ntp.org offline

The offline option can be useful in preventing systems from trying to activate connections. The chrony daemon will wait for chronyc to inform it that the system is connected to the network or Internet.