RE : Promiscuous Mode



Hello Simon,

Quite simple:
- no promisc: your NIC looks at the network, and takes only the packets destinated to it (gets the packets where "destination MAC address" = "NIC MAC address"),
- promisc: your NIC looks at the network, and takes ALL the packets it can get, whether they are adressed to it or not.

So, in a nutshell:
- no promisc: your NIC shows you only your trafic
- promisc: your NIC shows you all the trafic on the wire

HTH ...

________________________________

De: listbounce@xxxxxxxxxxxxxxxxx de la part de Simon Templar
Date: mer. 19/03/2008 14:51
À: pen-test@xxxxxxxxxxxxxxxxx
Objet : Promiscuous Mode



Hello everybody,

I have a question concerning "Promiscuous Mode", I know what it is,
but I would like to know exactly what is happening behind the scenes
when I change my NIC to this mode

For example: what is the technicality in writing the command:
ifconfig eth0 promisc?

Your help is so much appreciated.
Best regards.

------------------------------------------------------------------------
This list is sponsored by: Cenzic

Need to secure your web apps NOW?
Cenzic finds more, "real" vulnerabilities fast.
Click to try it, buy it or download a solution FREE today!

http://www.cenzic.com/downloads
------------------------------------------------------------------------






This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is prohibited.

------------------------------------------------------------------------
This list is sponsored by: Cenzic

Need to secure your web apps NOW?
Cenzic finds more, "real" vulnerabilities fast.
Click to try it, buy it or download a solution FREE today!

http://www.cenzic.com/downloads
------------------------------------------------------------------------



Relevant Pages

  • Re: [PATCH] 2.6.11 fix PROMISC/bridging in TLAN driver
    ... If promisc is enabled later it works. ... This means that if the interface is set to promiscuous mode during the time between initiation and the completion of autonegotiation, the interface will revert to non-promiscuous mode when the link becomes active. ... the problem manifests itself if the ethernet bridging module is being used and is initiated as part of the kernel start up process since bridging operation requires all of the slave interfaces to operate in promiscuous mode. ...
    (Linux-Kernel)
  • Re: How to permanently set a network interface to promiscuous mode?
    ... I think ifup-post already includes a clean way to extend its behavior ... How to permanently set a network interface to promiscuous ... What about adding support for PROMISC yourself in an init ... it always gets set to promiscuous mode. ...
    (RedHat)
  • Re: xl(4) autonegotiation trouble - ng_pppoe related?
    ... > can you please check if rp-pppoe does put the interface into promisc ... zero hints to promiscuous mode: ... ifconfig has no "PROMISC" tag, ... Encrypted mail welcome: my GnuPG key ID is 0x052E7D95 ...
    (freebsd-current)
  • [PATCH] 2.4.26 fix PROMISC/bridging in TLAN driver
    ... is switched into promiscuous mode before the link init is complete. ... kernel still thinks the card is in promiscuous mode but the card isn't. ... boot time (or something else that sets promisc at the same time the card ...
    (Linux-Kernel)
  • Re: Promiscuous Mode
    ... Setting an interface into promiscuous mode means it will not send ... I have a question concerning "Promiscuous Mode", I know what it is, ... buy it or download a solution FREE today! ...
    (Pen-Test)