No beacon activity

Jouni Malinen j
Sun Feb 6 03:13:12 PST 2011

On Thu, Feb 03, 2011 at 10:53:50AM -0800, Lara Deek wrote:
> 1) I am running a sniffer on the same machine A that is running hostapd. The
> sniffer does not capture beacon messages (only captures probe request and
> response packets, both broadcast and unicast). I ran a sniffer from another
> machine B (with a different card) in monitor mode, and B does in fact
> capture beacon messages (but never from A). Is there any reason why I do not
> sniff beacon frames on A? How can I fix this?

The actual Beacon frame transmission is not done by mac80211 and there
is no mechanism for the driver to indicate that a Beacon frame was
transmitted since this is not normally needed for anything. What would
you be using the Beacon frames for in the local sniffer?

> 2) I understand that hostapd only configures mac80211 with a template and
> beacon interval, but does not actually send beacons. Is enabling beacon
> transmission related to the firmware or driver? I have an AirMagnet C1060 PC
> card with an an Atheros, ath9k support, chipset that is not sending beacon
> messages. How should enable beacon transmission?

The driver is responsible for configuring Beacon frame transmissions.

How exactly did you verify that the card is not sending out Beacon
frames? Have you used another device in monitor mode to check that?

Jouni Malinen                                            PGP id EFC895FA

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