ntptrace Command for NTPv4

Purpose

Traces a chain of Network Time Protocol (NTP) hosts back to their primary time source.

Syntax

ntptrace [ -n ] [ -m maxhosts ][ server ]

Description

The ntptrace command is a perl script that uses the ntpq command to follow the chain of NTP servers from a specified host back to the primary time source. For ntptrace command to function correctly, each server must implement the NTP Control and Monitoring Protocol as specified in RFC 1305 and enable the NTP Mode 6 packets.

If no arguments are provided, the ntptrace command starts with localhost.

% ntptrace
localhost: stratum 4, offset 0.0019529, sync distance 0.144135
server2ozo.com: stratum 2, offset 0.0124263, sync distance 0.115784
usndh.edu: stratum 1, offset 0.0019298, sync distance 0.011993, refid 'WWVB'

Each line contains the following fields from left to right:

The hostname.
The host stratum.
The time offset between the specified host and the local host. The ntptrace command measures the time offset.
The host synchronization distance.
The reference clock ID is displayed only for the strarum-1 server.

All times are provided in seconds.

Note: The stratum is the server hop count to the primary source. The synchronization distance is the estimated error relative to the primary source. These terms are precisely defined in RFC 1305.

Flags

Table 1. Flags
Item	Description
-m `max_hosts`	Sets the upper-limit of the number of hosts to check for the primary time source. The default value is unlimited.
-n	Turns off the printing of the hostname. When -n option is specified, host IP addresses are printed instead of the hostnames. The -n flag is useful when a name server is down.

Parameters

Table 2. Parameters
Item	Description
`server`	Specifies the server. The default is the local host.

Exit Status

The ntptrace command returns the following exit values:

Table 3. Exit Status
Item	Description
`0`	Successful completion
`>0`	An error occurred

Security

Access Control: You must be a part of the system group to run this command.
Auditing Events: N/A

Examples

To trace the time source for the local host NTP server, enter the following command:
```
ntptrace
```

An output similar to the following output is displayed:

            loopback: stratum 5, offset 0.000076, synch distance 0.18291

            ganga08.in.ibm.com: stratum 4, offset -0.001854, synch distance 0.30600

            ganga10.in.ibm.com: stratum 3, offset 0.000251, synch distance 0.30550

            ausgsa.austin.ibm.com: stratum 2, offset -0.010158, synch distance 0.01921

            gsantp.austin.ibm.com: stratum 1, offset 0.016067, synch distance 0.00000, refid
          'GPS'

Files

/usr/sbin/ntp4/ntptrace4: Contains the ntptrace command for NTPv4.
/usr/sbin/ntptrace-->/usr/sbin/ntp4/ntptrace4: The default symbolic link to the NTP version 4 binary file from the /usr/sbin directory.