Network Time Protocol (NTP) configuration 400 Network Time Protocol (NTP) server Allow server to be configured even if not reachable Marks the server as unused Specifies the association as preemptable rather than the default persistent Marks the server as preferred Network Time Protocol (NTP) server options IP address ipv4net IP address and prefix length ipv6net IPv6 address and prefix length Addresses to listen for NTP queries ipv4 Network Time Protocol (NTP) IPv4 address ipv6 Network Time Protocol (NTP) IPv6 address