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** Version 2.0 Updated 9/16/99 - Now has round trip
time calculation
Mping is a simple command line application that sends
and receives multicast packets. It is invoked as:
Mping <IP address> [port] [TTL] [time in msec
between pings] [Loopback - 1 for yes 0 for no]
The command line arguments are:
IP address - required. IP multicast
address to send/receive on.
port - optional (defaults to 1711 if not specified). Port
number to send/receive on.
TTL - optional (default 16). Time to live for packets sent.
time in msec between pings - optional (default 1000) a packet
will be sent on the multicast address periodically according to this number of
milliseconds.
Loopback - optional (default 0) 1 if packets should be
received which originated from the same machine, 0 to ignore such packets.
To use:
Mping generates a new packet periodically, as
indicated by the time in msec between pings command line argument, and
prints "Sent packet". When it receives a packet, it prints a line of the form:
RCV: XX bytes from XXX.XXX.XXX.XXX Timestamp XXXXX
<descriptive string>
If the packet was not from Mping, the descriptive
string is "NON-MPING" and the Timestamp is omitted. If it is from MPING, then
the timestamp is printed from the header of the packet. This timestamp is set
by the sender, and is in milliseconds. The description string is set by the
sender in the packet header. For normal sends it is "MPING_PACKET". After
receiving a packet, the sender will change the description string to "Echoing
<IP address that sent the received packet>". This allows Mping to be run
continuously at a remote site, and by observing the echoed packets at another
site, it can be determined that the remote site can both send (since a packet
gets through) and receive (since it echos back an IP address that it received
from).
For packets that are echo'ed back to the sender, a
round trip estimation is made and printed.
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