[OT, embarrassing] trouble understanding ping output

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I have a script pinging my ISP (details below) and I don't understand
the results. Some output:

2391 Thu Feb 26 01:14:39 2009 -- 5 packets, time 45ms == max rtt: 351.654 ms
2392 Thu Feb 26 01:14:45 2009 -- 5 packets, time 46ms == max rtt: 344.855 ms
2393 Thu Feb 26 01:14:50 2009 -- 5 packets, time 46ms == max rtt: 340.359 ms
2394 Thu Feb 26 01:14:55 2009 -- 5 packets, time 47ms == max rtt: 345.226 ms
2395 Thu Feb 26 01:15:01 2009 -- 5 packets, time 46ms == max rtt: 356.115 ms
2396 Thu Feb 26 01:15:06 2009 -- 5 packets, time 47ms == max rtt: 350.294 ms
2397 Thu Feb 26 01:15:12 2009 -- 5 packets, time 57ms == max rtt: 341.351 ms
2398 Thu Feb 26 01:15:17 2009 -- 5 packets, time 58ms == max rtt: 350.854 ms

What I don't understand is how the maximum round trip time can be 350 ms
when it takes only 50 ms for the test. Can anyone explain this?

Details:
This is a perl script running on the server on my LAN. It does a 5
packet, 100 byte, ping flood (attempting to duplicate the Cisco router)
every 5 seconds. The output is collected and munged, and displayed with
the loop counter and a timestamp.

I'm doing this because a couple times a day, nagios (a new installation
on this same host) has been telling me the rtt to the ISP's border
router (T1, half a mile) has been high. The vast majority of the time,
the max rtt is 5 ms.

The host is *very* lightly loaded (both cores 95%+ idle). It runs lenny
from a software RAID1 on 2 SATA disks, no X.

There's another script, running at the same time on the same host, that
telnets into the router and pings from there. It's never reported a rtt
higher than 25 ms -- I'm assuming that means I've got a problem
somewhere, not the ISP / phone company.

My first problem is deciding what my problem is...

- --
Glenn English
ghe@xxxxxxxxxxx

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.8 (Darwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkmmsdMACgkQ04yQfZbbTLanEQCeNuXty6u2b27upSRWkCwfv7OI
sWkAnRMwuKL59Yi64MnaKY42qq1hLxXi
=BsC3
-----END PGP SIGNATURE-----


--
To UNSUBSCRIBE, email to debian-user-REQUEST@xxxxxxxxxxxxxxxx
with a subject of "unsubscribe". Trouble? Contact listmaster@xxxxxxxxxxxxxxxx

Relevant Pages

  • Re: How do I insert a cgi script into Publisher page?
    ... Each time I write ISP I keep telling my self that someone somewhere is going to go to AOL and look for their site, ... One is a straight forward form mailer working with publisher forms and the other is script form that requires the sender to put in a 4 number code to send. ... Though Publisher uses 'ISP' I think that may be confusing to some as my ISP is not where I host my website. ... If your ISP supports cgi and has a form handling program then a form created in publisher will function using FTP upload rather than front page server extensions to upload the pages. ...
    (microsoft.public.publisher.webdesign)
  • Re: How do I insert a cgi script into Publisher page?
    ... Your way of using Google to find the relevant help information on a host ... Though Publisher uses 'ISP' I think that may be confusing to some as my ... If your ISP supports cgi and has a form handling program then a form ... or any where else you so desire or an auto redirect script with a delay. ...
    (microsoft.public.publisher.webdesign)
  • Re: Cannot instantiate non-existent class
    ... include it - contact your ISP and ask them what to do :-) ... The problem is - when you access it through http, all you get is the HTML generated by the script. ... IIWY I would go back to the host and get a better answer. ... includeis a very basic statement, and used *very* heavily in PHP. ...
    (comp.lang.php)
  • Re: internet proxy
    ... Is it possible to create separate shortcuts to IE - one with 'proxy server ... This script gets used when you enable the "Automatically ... connect to the host so no proxy would get used. ...
    (microsoft.public.windowsxp.general)
  • Re: How do I insert a cgi script into Publisher page?
    ... is not where I host my website. ... If your ISP supports cgi and has a form handling program then a form ... You must tell the server what e mail address you want the form results ... any where else you so desire or an auto redirect script with a delay. ...
    (microsoft.public.publisher.webdesign)