HP-UX Internet Services Administrator's Guide (February 2007)

NOTE: xntpd is an HP implementation of version 3.2 of a publicly-available NTP
daemon. HP does not guarantee that xntpd is fully compatible with version 1 or version
2 implementations of the daemon.
Configuring an External Clock
Clocks are normally configured with server statements in the configuration file. You
can configure xntpd to support an external clock. You can insert the clock address
anywhere in the configuration file.
Clocks are referenced by an address of the format 127.127.t.u, where t specifies
the clock type and u specifies the unit number, which depends on the clock type for
interpretation (this allows multiple instances of the same clock type on a single host).
xntpd supports the following clocks:
• Netclock/2 WWVB Synchronized Clock.
A stratum-1 server is configured with this type of clock. The address used to
configure the clock is 127.127.4.u, where u is a value between 1 and 4. You
must also create a device file /dev/wwvb%u.
• Local Synchronization Clock (pseudo clock)
A system with this type of clock uses the local system clock as a time source. The
address used to configure this clock is 127.127.1.u, where u is a value between
0 and 15 and specifies the stratum level at which the clock runs. When you
synchronize the local host to this clock, the local host operates at one stratum level
higher than the local clock. You can use this type of clock in an isolated
synchronization subnet, which does not have access to a stratum-1 time server.
For more information on configuring external clocks, type man 1M xntpd at the HP-UX
prompt.
Figure 4-4 shows the peer, server, and broadcast statements that are configured for all
the servers.
64 Configuring NTP