I haven't used Net::SSH::Perl, but I have used Net::SSH::Expect to do basically the same thing. Connecting to a bunch of servers to check for failures and do basic configuration management reporting.
Here is a chunk of the code, hope it helps.

        my $ssh = Net::SSH::Expect->new (
                host => "$serverlist[$host]",
                user => "$user",
                raw_pty => 1,
                restart_timeout_upon_receive => 1,
                timeout => 6,
                ssh_option => " -x",
        );


        # Validate that we have a successful ssh connection
        $login_output = $ssh->run_ssh() or die "Couldn't start ssh pro
+cess, error $!\n";

        sleep(1);

        my $ret;
        my $rc1 = eval{$ret = $ssh->read_all(12);};
        unless($rc1) {
                open(NOCON,">>$NOCONNECT");
                print NOCON "$serverlist[$host] - Could not connect --
+ skipping.\n";
                close(NOCON);
                $pm->finish(0);  # Couldn't connect to this one, skip 
+to next server in main loop

        }

        my $rc = eval{( $ret =~ />\s*|$\s*\z/) or die "where's the rem
+ote prompt?";};
        if($rc) {
                if($ret =~ m/[Pp]assword:/) {
#                       print("Server asking for password, key not ins
+talled.\n");
                        open(NOCON,">>$NOCONNECT");
                        print NOCON "$serverlist[$host] - Asking for p
+assword -- skipping.\n";
                        close(NOCON);
                        $pm->finish(0);    # Couldn't connect to this 
+one, skip to next server in main loop
                }
        }


        $ssh->exec("stty raw -echo");

        # Start issuing the commands to check
[download]

Also note that I have pm->finish, which is part of Parallel::ForkManager, which allows me to connect to "n" servers at once, and not have to do them in sequence. If you have a lot of servers to check, I'd recommend at least looking into that.

Hope that helps.