Try "promiscuous mode" in google.  You can also learn about it on 
Wikipedia -- http://en.wikipedia.org/wiki/Promiscuous_mode . An old thread 
that may interest you begins at 
http://www.derkeiler.com/Newsgroups/comp.os.linux.security/2003-09/0580.html
     Since computers usually are run in non-promiscuous mode, in which they 
only look at packets intended just for them, and since evildoers sometimes 
use captured computers to look at all the packets coming by, it's a bad 
sign if promiscuous mode is enabled and you don't remember doing it.  But 
it doesn't necessarily mean your computer has been hacked.
     You can enable and disable promiscuous mode with ifconfig (do "man 
ifconfig" and look for "promisc").  The command "/sbin/ifconfig -a" shows 
information about each network interface.  A line with "PROMISC", such as

BROADCAST PROMISC MULTICAST  MTU:1500  Metric:1

shows that the network interface is in promiscuous mode.

Steven Yellin

On Wed, 9 Jul 2008, Arturo Fatturi wrote:

> Hello to all.
>
> I am finding some trouble with the following message at boot:
>
> eth0 promiscuous mode enable.
> eth0 promiscuous mode enable
> eth0 promiscuous mode enble
>
>
> I do not know wath this means: I can acces the
> web but do not install any extra software.
>
> Yum are reporting error : canot acces freshrpms.
>
> Wath is a "promiscuous mode enable". My
> computer is victim of hackers?
>
> Thanks for any advice.
>
> Arturo Fatturi
>
> Brazil
>