in reply to How to use "$ssh->before()"

I want to know peer ip is alive or not.

If you know the peer IP addresses, use Net::Ping module to ping set of IP addresses,

Ex,

    use Net::Ping;

    my $p = Net::Ping->new("icmp");
    my @host_array = (IP1,IP2,IP3...);

    foreach $host (@host_array)
    {
        print "$host is ";
        print "NOT " unless $p->ping($host, 2);
        print "reachable.\n";
        sleep(1);
    }
    $p->close();

[download]
All is well. I learn by answering your questions...

Replies are listed 'Best First'.
Re^2: How to use "$ssh->before()"
by ww (Archbishop) on Apr 15, 2015 at 11:59 UTC

    or, alternately (because using icmp may require addtl info)...

    #! /usr/bin/perl -w
use 5.018;

# cf [id://1123481] -> my $p = Net::Ping->new("icmp");  
# method not allowed by (some) hosts, YMMV!

my @host_array = ('n+.n+.n+.n+', 'n+.n+.n+.n+', .... );

say "\n Pinging so-and-so(s)\n";

use Net::Ping;

my $p = Net::Ping->new("syn");
for my $host (@host_array) {
    if ($p->ping($host) ) {
        say "Host $host is alive \n  (at least, 'arguably' See doc re 
+'syn' protocol)\n";
    } else {
        say "Could not ping host $host, $!";
    }
$p->close();
}

    [download]
[reply]
[d/l]

In Section Seekers of Perl Wisdom