Re: Internet Connection Sensor

Another reason to not acknowledge PING is to avoid making your computer a target. Most useful on a home computer. Check out Steve Gibson's web site www.grc.com. He has a section headed Shields Up!. The site was hit with DoS a few years ago. Since then, in addition to the computer products that he sells (SpinRite for one), the site provides information on computer security, and will test your shields, if you allow. He specifically does not like for sites to acknowledge a PING.

John McKee

-----Original message-----
From: "Mark S. Waterbury" mark.s.waterbury@xxxxxxx
Date: Wed, 20 Jan 2010 11:56:08 -0600
To: Midrange Systems Technical Discussion midrange-l@xxxxxxxxxxxx
Subject: Re: Internet Connection Sensor

Hi, Alan:

> Alan Shore wrote:

Be careful in relying on PING
Some sites do not PING, even when they are up
Why? Don't know

Why? Many firewalls have rules to block pings, to stave off "ping of
death" attacks, or a "ping flood" (denial of service attack) etc. -- see:

http://en.wikipedia.org/wiki/Ping_of_death
and
http://en.wikipedia.org/wiki/Ping_flood

Cheers,

Mark S. Waterbury
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