1 .\" Copyright (c) 2008 George V. Neville-Neil
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40 .Op Fl t Ar inter-packet gap
41 .Op Fl M Ar number of clients (source only)
42 .Op Fl m Ar my client number (sink only)
47 command implements a multicast test which involves a source
49 The source sends packets to a pre-configured
50 multicast address over the interface given as a command line
52 The sink listens for multicast packets, records
53 the time at which they are received and then reflects them back
54 over unicast to the source.
55 When the source has captured all
56 the reflected packets it prints out the round trip time of each.
58 The source prints out the round trip time of packets sent to the
60 The sink prints out the time between the packets received.
62 The options are as follows:
63 .Bl -tag -width ".Fl i Ar interface"
65 Network interface, which can be found with
70 Port on which to listen.
76 Inter-packet gap in nanoseconds.
78 The number of clients that are listening.
80 The client's number 0, 1, etc.
84 is the receiver aka the sink.
86 only be used with one copy of the program at a time.
89 The following is an example of a typical usage
95 .Dl "mctest -i em0 -M 1 -s 1024 -n 100 -t 1"
97 .Dl "mctest -i em0 -m 0 -s 1024 -n 100 -r"
99 Send 100 packets of 1024 bytes, with an inter-packet gap of 1 nanosecond.
101 Gaps are measured with
103 and so are not accurate down to nanoseconds
104 but depend on the setting of
113 program first appeared in
117 manual page was written by
118 .An George V. Neville-Neil Aq gnn@FreeBSD.org .
120 Should be reported to the author or to
121 .Aq net@FreeBSD.org .