This is part of The Pile, a partial archive of some open source mailing lists and newsgroups.
Subject: Re: how to suid a perl script
From: "Steve \"Stevers!\" Coile" <scoile@redhat.com>
Date: Mon, 24 May 1999 17:06:58 -0400 (EDT)
On Mon, 24 May 1999, Clarence Donath wrote:
>Having tried this exercise recently myself, I finally concluded that you
>need to be logged in as root in order to ping using icmp. I believe that
>if you try pinging using the 'tcp' protocol that it will work for you.
Pinging via TCP isn't really pinging (technically). However, using TCP to
test connectivity is sometimes more reliable than using ICMP, since some
sites filter ICMP echo requests ("pings") at the router to prevent ping
floods. On the other hand, the TCP "ping" used by the Perl module (which
module was it?) tries to connect to a trivial service typically provided
via Inetd, such as "echo" or "chargen". Many sites disable these trivial
services because: (a) they're very seldom used by any applications; (b)
mostly only used for diagnostic purposes anyway, but better utilities
exist; and (c) can easily be used in denial-of-service attacks.
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