RFR: 8219804 ava/net/MulticastSocket/Promiscuous.java fails intermittently due to NumberFormatException

[Michael McMahon]

Small test case update. The test has failed a couple of times where it 
appears
to be receiving input on a multicast socket which could not be generated 
by the test case itself.
The test happens to use multicast groups that are assigned by IANA, and 
globally routable.
So, it is conceivable that other entities are sending packets picked up 
by the test.
The test also does not protect against other instances of itself running 
on different hosts
at the same time, though that doesn't seem to be the cause of this failure.
The change is to use non-routable multicast groups and to add some 
hopefully unique data
to the test in case the test might be running on multiple hosts on the 
same subnet simultaneously.

http://cr.openjdk.java.net/~michaelm/8219804/webrev.1/index.html

Thanks,
Michael.