1NSM(8)                      System Manager's Manual                     NSM(8)
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NAME

6       nsm - NetSync Monitor client
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SYNOPSIS

10       nsm [ -f config ] [ -i interface ] [ long-options ] [ command ] ...
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DESCRIPTION

14       nsm  is  a program which implements a NetSync Monitor (NSM) client. NSM
15       is an extension to the Precision Time Protocol (PTP), which  enables  a
16       client  to measure the offset of its clock against any PTP clock in the
17       network which supports NSM. It uses unicast messages, but unlike PTP in
18       the  unicast mode it does not require the server to keep any state spe‐
19       cific to the client. It is particularly useful for monitoring.
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21       The program reads commands from the standard input or from the  command
22       line.
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COMMANDS

26       NSM address
27              Send  a NetSync Monitor request to the specified network address
28              (IPv4 or MAC) and print the measured offset with the response.
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30       help   Display a help message.
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OPTIONS

34       -f config
35              Read configuration from the  specified  file.  No  configuration
36              file is read by default.
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38       -i interface
39              Specify the network interface.
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41       -h     Display a help message.
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43       -v     Print the software version and exit.
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LONG OPTIONS

47       Each  and  every  configuration file option (see below in sections PRO‐
48       GRAM OPTIONS and PORT OPTIONS) may also appear as a "long"  style  com‐
49       mand  line  argument.  For example, the transportSpecific option may be
50       set using either of these two forms:
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52              --transportSpecific 1   --transportSpecific=1
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54       Option values given on the command line override values in  the  global
55       section  of  the  configuration file (which, in turn, overrides default
56       values).
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CONFIGURATION FILE

60       The configuration file is divided into sections.  Each  section  starts
61       with  a  line  containing  its name enclosed in brackets and it follows
62       with settings.  Each setting is placed on a separate line, it  contains
63       the  name  of  the option and the value separated by whitespace charac‐
64       ters. Empty lines and lines starting with # are ignored.
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66       The global section (indicated as  [global])  sets  the  global  program
67       options  as  well as the default port specific options.  Other sections
68       are port specific sections and they override the default port  options.
69       The  name  of  the  section  is  the  name of the configured port (e.g.
70       [eth0] ).
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PORT OPTIONS

74       delayAsymmetry
75              The time difference in nanoseconds of the transmit  and  receive
76              paths.  This  value  should be positive when the master-to-slave
77              propagation time is longer and negative when the slave-to-master
78              time is longer. The default is 0 nanoseconds.
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80       network_transport
81              Select  the network transport. Possible values are UDPv4 and L2.
82              The default is UDPv4.
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84       transportSpecific
85              The transport specific field. Must be in the  range  0  to  255.
86              The default is 0.
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PROGRAM OPTIONS

90       domainNumber
91              The  domain  attribute  of  the  local  clock. The default is 0.
92              time_stamping The time stamping method. The allowed  values  are
93              hardware, software and legacy.  The default is hardware.
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WARNING

97       Be cautious when the same configuration file is used for both ptp4l and
98       nsm.  Keep in mind that values specified in the configuration file take
99       precedence over their default values. If a certain option which is com‐
100       mon to ptp4l and nsm is specified to a non-default value in the config‐
101       uration file (e.g. for ptp4l), then this non-default value applies also
102       for nsm. This might be not what is expected.
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104       To avoid securely these unexpected behaviour,  different  configuration
105       files for ptp4l and nsm are recommended.
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SEE ALSO

109       ptp4l(8)
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113linuxptp                           June 2019                            NSM(8)
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