'msend' and 'mrcv' are respectively multicast sender and multicast receiver
tools for multicast routing debugging. They don't have any "user friendly"
interface, but give you a simple and sufficient control for debugging.
Type "?" for help after you start msend or mrcv. Usually the way I use them is:
1. mrcv:
j 224.0.1.20 172.16.1.2
r 224.0.1.20 12321

2. msend:
i 172.16.10.10
t 5
s 224.0.1.20 12321

NOTES:
 * 172.16.1.2 and 172.16.10.10 are respectively the IP addresses of
   the interfaces of the receiver and sender you want to receive/send
   the mcast data on.
 * 224.0.1.20 is a mcast group reserved for experiments. Better use this
   one for your experiments instead of choosing some other group
 * 12321 is the UDP port number you want to use. If you somehow get a
   bind errors "Address in use" or something like that when you
   execute the 'j' command, you may want to choose some port that
   is not in use ('netstat -an' will show the list of ports that are
   in use on the receiver machine). Though, this shoudn't happen if you
   are binding to both an address and a port...
 * 't 5' will limit the number of hops your mcast pkts will travel to
   just 5 hops away. Always a good idea to restrict the number of hops
   for multicast, othewise your mcast pkts may be propagated to places they
   are not suppose to go.


Pavlin Radoslavov
pavlin@catarina.usc.edu
Thu Dec  7 06:37:42 PST 2000

Acknowledgments:
msend and mrcv were originally written by Puneet Sharma
(puneetsh@catarina.usc.edu) and Polly Huang (huang@catarina.usc.edu). I did
some minor changes + packet format modification, so you must use them in pair.

TODO:
 1) Allow command line parameter specification.
 2) Verify the rate specification is correct.

