rsh woes, please help.

[Rhugga]

We are having problems with rsh on 7.2 machines. We are doing massive rsh connections on a 250-node cluster executing PVM jobs. We reach a point where we get the following error: (single machine test)   poll: protocol failure in circuit setup   It happens around 500 or so connections. I wrote test scripts that spawned rsh connections in sequence doing a simple 'uname -S' and found that near 500 connections this error would occur. Note: It is not always the same amount, it may be 497, 495, 499, but never 500.   Is there a limit on open sockets or is there a limitation in in.rshd? These machines are otherwise idle when these tests are being ran.   Also, is there a way to run in.rshd in daemon mode or is there any code out that that can do what in.rshd does?   Thanks, Chuck