[TriLUG] OT: Amiable ping target

[William Sutton]

FYI, here is a little keep-alive script I use for my shells outside $WORK 
(so the session doesn't time out).  It should be a quick thing to modify 
for your purpose:

#####

#!/usr/bin/perl
use strict;

my @hosts = (
    "yahoo.com",
    "google.com",
    "newsobserver.com",
);

while()
{
    my $items = scalar(@hosts);
    my $item  = int($items * rand());
    `ping -c 1 $hosts[$item]`;
    print ".";
    `sleep 20`;
}

#####

the my @hosts ... portion could easily be modified to read from a file as 
follows:
1. install File::Slurp
2. add 'use File::Slurp;' after 'use strict;'
4. replace 'my @hosts = ( ... );' with the following snippet:

my @hosts = map { chomp($_); $_; } read_file("your_host_file.txt");

best of luck...


On Fri, 26 Aug 2005, Brian Henning wrote:

> Hi Folks,
>    Pardon my ignorance...but is there an IP somewhere out there that is 
> specifically set up to be a ping target for checking connectivity? 
> We're having some serious issues with our DSL here lately, and I want to 
> set up a task to monitor it with pretty high resolution, say, around one 
> ping per second (I have a feeling some of its frequent flakings are only 
> seconds in length, but enough to interrupt our VPN).
> 
> Obviously, doing this sort of thing would require a target (or more 
> probably, list of targets) that are highly reliable themselves, to avoid 
> false down indications.  So I'd probably create a list of N targets, and 
> each would only see a ping from me every N seconds unless one failed, in 
> which case the process would ping the next target on the list immediately.
> 
> My concern, of course, being a [hopefully] nice little Net citizen, is 
> not wanting to irritate anyone by taking about 302kB out of their 
> transfer quota every hour (3600 pings * 84 bytes each), unless they're 
> intending to be so generous.
> 
> In other words, I have a feeling I shouldn't just randomly choose some 
> hosts (unless I choose a huge number of them...a possibility).  Hence 
> the question.
> 
> And as a sideline question, if there's a nice utility out there already 
> to do something like that (take a list of hosts and ping one every X 
> seconds and report on the success), I'd love to know about it.
> 
> Thanks a bunch as always!
> ~Brian
>