2002-01-10 21:00:11

by Balazs Javor

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Subject: eth0: entered promiscuous mode

Hi,

Can somebody please tell me what the above message means?

I very often encounter this in the syslog and sometimes
also on the console.

Many thanks for yout help in advance!
best regards,
Balazs


2002-01-10 21:28:53

by Andreas Dilger

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Subject: Re: eth0: entered promiscuous mode

On Jan 10, 2002 21:59 +0100, Balazs Javor wrote:
> Can somebody please tell me what the above message means?

It means that you are running a program like "tcpdump". If not, it
may mean that someone has hacked into your system and is running a
network sniffer to capture passwords on your network.

Cheers, Andreas
--
Andreas Dilger
http://sourceforge.net/projects/ext2resize/
http://www-mddsp.enel.ucalgary.ca/People/adilger/

2002-01-10 21:32:33

by Bernd Eckenfels

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Subject: Re: eth0: entered promiscuous mode

In article <[email protected]> you wrote:
> Can somebody please tell me what the above message means?

it means you run a root program which requested the network card to go into
promic mode. promisc mode means, the card will receive all packets on the
wire, not only those destinated to the card. a few sniffing/scan
detector/accounting apps require this, and some legal apps for network
configuration (like dhcp/bootp/... ) and arpwatch may require it.

Greetings
Bernd

2002-01-10 22:24:39

by David C P Gray

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Subject: Re: eth0: entered promiscuous mode


On Thu, 10 Jan 2002, Bernd Eckenfels wrote:

> In article <[email protected]> you wrote:
> > Can somebody please tell me what the above message means?
>
> it means you run a root program which requested the network card to go into
> promic mode. promisc mode means, the card will receive all packets on the
> wire, not only those destinated to the card. a few sniffing/scan
> detector/accounting apps require this, and some legal apps for network
> configuration (like dhcp/bootp/... ) and arpwatch may require it.

VMware can also trigger this message. It uses promiscuous mode to
provide access to the LAN for guest OS sessions.

Cheers,
David.



2002-01-11 03:42:37

by Robert Love

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Subject: Re: eth0: entered promiscuous mode

On Thu, 2002-01-10 at 15:59, Balazs Javor wrote:

> Can somebody please tell me what the above message means?
>
> I very often encounter this in the syslog and sometimes
> also on the console.

Promiscuous mode means the network card will snag packets even if they
are not delivered to you. Typically, only ethernet frames whose MAC
address matches you or broadcast are processed by the NIC. Thus, your
NIC can read any and all packets on your network.

Are you sniffing your coworkers or something ? ;)

Robert Love