Passive/Active scanning information

Hi. I have some question related to 802.11 handoff mechanism.

  1. Does anybody know more information about TIM related field from beacon frame format, and how is modeled information offered by it. I read from IEEE 802.11 standards, but I didn't understand so well.

  1. If my NETGEAR WAG511 drivers is in monitor mode, can I send probe request? Also, it's another mode where I can use passive scanning, but also send traffic? I suppose in monitor mode, doesn't want to work, no?

  2. If I can't send data traffic in monitor mode, why I can send ping packages. What kind of ICMP traffic is ping pong?

Thanks in advance, Robert

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RobertGrandl
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RobertGrandl hath wroth:

None of your questions have anything to do with handoff (roaming).

TIM broadcasts are used for power management, where the client power is shut off for an interval when the access point is going to be busy servicing other clients. Only clients that have power save mode enabled will react to the TIM interval. Most clients run in power save mode = off because it impacts performance. Note that it is not the same as the ATIM interval, which is just the beacon interval.

This might be a bit simpler than the IEEE 802.11 specs, which tend to turn the brain into mush.

Also, search Google for "TIM interval" and "traffic indication map".

You can send probe requests in any mode you feel like. It's the first packets that get sent when initiating a new connection in any mode asking essentially "who is out there"? It's also the way Netstumbler works.

Dunno. Probably not. Trying to seperate valid incoming data from sniffed data is going to be a challenge.

Dunno. I have no idea what you are doing or trying to accomplish.

See RFC792. ICMP type list:

Note that there is also UDP Ping.

Reply to
Jeff Liebermann

Thank you very much Jeff for your amability. Indeed wireless standard documentation sometimes it's not the best to understand some specific and exactly problems.

Thanks, Robert

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RobertGrandl

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