Hey guys,

I've got a simple engine which forks and attempts to make simaltaneous ssh connections to various (and different) hosts.

To do this, I'm using Parallel::ForkManager and the Net::SSH::Perl module.

My problem is that if I attempt to make these ssh connections in parallel/simaltaneously, then they are always unsuccessful.

With debug mode on, Net::SSH::Perl outputs 

Verifying server signature.
Waiting for NEWKEYS message.
Enabling incoming encryption/MAC/compression.
Send NEWKEYS, enable outgoing encryption/MAC/compression.
Sending request for user-authentication service.

[download]

before croaking with the message: 

Connection closed by remote host. at /usr/lib/perl5/site_perl/5.8.0/Ne
+t/SSH/Perl/AuthMgr.pm line 43

[download]

Yet if I make my engine make these connections in a 'one at a time' fashion by setting Parallel:ForkManagers max probes setting to 1, then they always connect in succession without a problem.

My code for an ssh connection is very simple.

#!/usr/bin/perl -w

use strict;
use Net::SSH::Perl;

my $sshusername = "anthski";
my $sshpasswd = "somepassword";
my $host = "192.168.0.1";

my $command = "date";

my $ssh = Net::SSH::Perl->new($host, debug => 1, protocol => 2);
my $loginStatus = $ssh->login($sshusername,$sshpasswd);

my $stdout;
my $stderr;
my $exit;

eval {
        ($stdout,$stderr,$exit) = $ssh->cmd($command);
};

if ($@)
{
        if ($@ =~ m/Permission denied/i) {
                print "Authentication failed\n";
                exit 1;
        }
}

print "$stdout\n";

[download]

The remote servers are a mix of solaris and redhat boxes (7.3 and AS4). All the connections work by hand as well as when run individually.

Has anyone ran into a similar problem? Anyone with any gotchas to share about Net::SSH::Perl and simaltaneous connections, or any advice (which may be non-Perl orientated) about why these connections may fail? Perhaps there's some ssh_config option that I need to pass...

cheers,
Anth

In reply to Net::SSH::Perl and simaltaneous connections by anthski

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