[nSLUG] Error with rsh after several error-free exchanges
mspencer at tallships.ca
Sat Oct 18 04:20:03 ADT 2014
I have a script that tries to do rsh several hundred times between two
It runs as expected for a few instances, then begins to report:
poll: protocol failure in circuit setup
repeatedly and and fails to return any further data to the client host.
Google turns up cases where rsh failed completely, was enabled by
closing down the firewall. Mine works fine a few times, THEN fails.
A subsequent rsh command executed from the keyboard works. In any
case, iptables at both hosts has:
Chain INPUT (policy DROP)
ACCEPT all -- localnet/27 anywhere
Chain OUTPUT (policy DROP)
ACCEPT all -- anywhere anywhere state NEW,RELATED,ESTABLISHED
The manpage for inetd(8) says, about the "shell...in.rshd" line in
The optional ``max'' suffix (separated from ``wait'' or ``nowait''
by a dot) specifies the maximum number of server instances that
may be spawned from inetd within an interval of 60 seconds. The
default is unlimited
/usr/bin/rsh is -rws--x--x.
This is between 2 machines on my LAN, not over the public internet so
security isn't a problem.
My guess is: something about the source ports chosen for the replies but
I don't have a clue how to control that. I haven't packet-sniffed the
exchange to verify that guess.
Suggestions? Is this a well-known thing that cluless folks such as I
Michael Spencer Nova Scotia, Canada .~.
mspencer at tallships.ca /( )\
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