OSF DCE Administration Guide--Core Components

OSF DCE Administration Guide—Core Components
26.2 Giving the Time to NTP Nodes
Any DTS server or clerk that runs the ntpd daemon or the xntpd daemon with the -s
option and a special configuration file (ntp.conf) can be configured as an NTP server.
For systems running the ntpd daemon, the ntp.conf configuration file must contain the
following line:
peer /dev/null DTSS 8 -5 local
In addition, add -s to the ntpd entry in the file /sbin/init.d/ntpd or, for systems with
rc.local, modify the line that starts ntpd accordingly.
For systems running the xntpd daemon, the ntp.conf configuration file must contain the
following line:
peer 127.127.1.8
In addition, add -s to the xntpd entry in the file /sbin/init.d/xntpd or, for systems with
rc.local, modify the line that starts xntpd accordingly.
In this configuration, NTP never sets the clock. NTP can, however, give the time to other
NTP clients. Do not allow loops between DTS and NTP to form. If NTP gives the time
to DTS, then DTS gives the time back to the same set of NTP servers, unexpected results
can occur.
The NTP configuration file is set up to ensure that an NTP server that obtains the time
from DTS is a Stratum 8 node. In addition, dts_ntp_provider is prohibited from
accepting time from a node at Stratum 8 or higher.
A DTS (server) node can give time to an NTP node if the following rules and advisories
are observed:
• Rule—The ntp.conf file must declare this node at Stratum 8.
• Advisory—Multiple nodes in the set can be running ntpd -s or xntpd -s.
• Advisory—If any DTS-managed system has a local time source, that system should
be used as an NTP -s server.
• Advisory—Although this operation can occur on either a DTS server or a DTS client
node, a DTS server is preferred.
Note: If null providers are used, the rules in Section 26.1.1 must also be followed,
since null providers running on NTP nodes can bypass the stratum check.
Figure 26-4 shows two DTS server nodes running ntpd -s and providing time to an NTP
subnetwork. The ntp.conf file defines these servers at Stratum 8.
Figure 26-4. Giving the Time to NTP
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