[technique] Wifi au RIPE 65

Laurent GUERBY laurent at guerby.net
Mar 16 Oct 13:40:03 CEST 2012


Une experience interessante en dual band 2.4 et 5 GHz
avec "band steering" activé et des clients Linux.



Band steering

The new wireless network SSID we used for the recent RIPE 65 meeting in
Amsterdam was configured to use band steering. This is used to encourage
users to prefer a 5GHz network, which has many more channels to play
with. This seems to work fine with both Windows and Mac clients;
unfortunately, wpa_supplicant (Linux & FreeBSD) does not support band
steering. There is a Redhat bug report and a post discussing the issue
on a Debian platform.

Band steering causes an access point to silently drop probe requests on
the 2.4GHz network, if it knows a client is capable of 5GHz. If
wpa_supplicant decides that a 2.4GHz network BSSID is the best thing to
connect to, it will try to connect to it. When it times out, it retries
3 times, blacklists the Access Point (AP) and tries to connect to
another one. It does not try the same BSSID over 5GHz, whereas the band
steering setup assumes it will.

During the RIPE 65 meeting, there were 468 attendees and we had a peak
of 500 wireless clients on the wireless network. 7% of these were Linux
users who could potentially have had problems. In the end only 7
attendees reported problems with their wireless connectivity.

-------- Forwarded Message --------
From: Mirjam Kuehne <mir at ripe.net>
To: ncc-services-wg at ripe.net
Subject: [ncc-services-wg] New on RIPE Labs: Wi-Fi Issues During RIPE 65
Date: Tue, 16 Oct 2012 12:24:37 +0200

Dear colleague,

During the recent RIPE 65 meeting, some attendees experienced problems 
with the wireless network. Together with these attendees we investigated 
the problem. Please find a detailed report on RIPE Labs:


Kind regards,
Mirjam Kuehne

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