Configuration listen on: tell ntpd to listen on a specific IP or all IPs listen on * listen on 127.0.0.1 can occur multiple times server: sync to a single server if given as hostname that resolves to more than one IP, use the first one. If we don't get a reply from that, pick the next one and retry servers: sync to a set of servers (pool.ntp.org) if given as hostname that resolves to n IPs, treat as if n "server $ip" statements were given