Comment 90 for bug 291760

Installing wicd makes this problem go away. Here's my story.

I have a wireless network with a 802.11g dlink router and WEP key. I use two machines, a MacbookPro revision 4 with a Atheros Communications Inc. AR5008 Wireless Network Adapter (rev 01) and a mac mini.

The macbook pro runs ubuntu 9.04 and ath9k with NetworkManager and had a syslog clogged with and a consistently terrible connection:

Aug 26 22:45:32 orbital NetworkManager: <debug> [1251351932.002555] periodic_update(): Roamed from BSSID 00:13:46:F1:27:35 (Trouble2) to (none) ((none))
Aug 26 22:45:38 orbital NetworkManager: <debug> [1251351938.002259] periodic_update(): Roamed from BSSID (none) ((none)) to 00:13:46:F1:27:35 (Trouble2)
Aug 26 22:47:32 orbital NetworkManager: <debug> [1251352052.001406] periodic_update(): Roamed from BSSID 00:13:46:F1:27:35 (Trouble2) to (none) ((none))
Aug 26 22:47:38 orbital NetworkManager: <debug> [1251352058.001944] periodic_update(): Roamed from BSSID (none) ((none)) to 00:13:46:F1:27:35 (Trouble2)
Aug 26 22:49:32 orbital NetworkManager: <debug> [1251352172.003147] periodic_update(): Roamed from BSSID 00:13:46:F1:27:35 (Trouble2) to (none) ((none))
Aug 26 22:49:38 orbital NetworkManager: <debug> [1251352178.002056] periodic_update(): Roamed from BSSID (none) ((none)) to 00:13:46:F1:27:35 (Trouble2)

Every two minutes, like clockwork, I would get large amounts of lag and dropped pings.

On OSX, I had several pings running at the same time I was running 'watch --interval=.1 iwconfig wlan0', 'ping 192.168.0.1', and 'tail -f /var/log/syslog'

I could plainly see exactly what was happening:

Every two minutes, I would drop about 50-60 icmp sequence pings to the router on the Ubuntu machine at the same time that Frequency on the iwconfig would jump all over the place and the syslog would shortly after report that there was a roam to none none. At the same time that this roam scan was happening, the OSX Mac Mini's pings would not be dropped, but would be lagged from 2-3 ms to 1-3 SECONDS.

Not only is this NetworkManager a,b,g background scan totally ruining my connection, it's hurting the connection of any near by computers.

Installing wicd is the only thing that helped. And this regression of a,b,g background scanning while connected makes NetworkManager unusable for me and a detriment to anyone on the same network while I'm using it.

I'll be using wicd until NetworkManager is PROPERLY fixed.