> On Wed, Aug 15, 2018 at 9:36 AM, Dan Williams via networkmanager-list < [email protected]> wrote > > Does the switching cause an actual problem? It's supposed to happen > very quickly, within a couple 10s of ms.
I have run into like roaming/band-selection issues with linux around various wireless environments for some time, pretty much any time I've has 2.4ghz and 5ghz co-existence on the same ssid's. I seem to remember the few times I've gone to look into it, there was no granular way to control 2.4/5ghz either with iwconfig, wpa_supplicant, or nm, other than mentioned static bssid, which is messy when you have more than one ap around in high-density deployments. It seems it's just far too hair-trigger to flip between AP's, and even enabling band-steering features on enterprise ap/controller side doesn't really seem to help influence which band a linux system will end up using. I'm presuming it chooses generally the best rssi, which 2.4 will probably always win, and often I'll get my systems just refusing to use a 5ghz in places when available. It would be nice to have a bit better local control over band selection, roaming sensitivity, and other client radio behaviors since there really is no native ccx-like support to control better these things in enterprise environments, and consumer multi-ap solutions like this samsung probably don't even properly offer any proper roaming support to control client behavior in the first place. -mb On Wed, Aug 15, 2018 at 9:36 AM, Dan Williams via networkmanager-list < [email protected]> wrote: > On Tue, 2018-08-14 at 23:04 -0500, Greg Oliver via networkmanager-list > wrote: > > On Tue, Aug 14, 2018 at 2:24 PM "Jürgen Bausa" <[email protected]> > > wrote: > > > > > I have a Xiaomi Air 12 Laptop (Intel Core m3-7Y30, Network > > > controller: > > > Intel Corporation Wireless 8260 > > > (rev 3a)). I use debian Stretch (linux 4.9.0-7-amd64) with KDE and > > > Network-Mananger (1.6.2-3). > > > > This is behavior specific to wpa_supplicant and how it decides to roam > between access points. It attempts to roam to a BSSID within the same > SSID that has a better speed/signal. It is expected that it might jump > between BSSIDs when conditions change. > > Does the switching cause an actual problem? It's supposed to happen > very quickly, within a couple 10s of ms. > > Dan > > > > Until now, wifi worked fine. However, after I exchanged my router > > > (which > > > had only 2.4 GHz) against a > > > newer model that has both 2.4 and 5 GHz (both frequencies with the > > > same > > > ssid), I experienced the > > > following problem: The computer switches permanently between both > > > frequencies. This happens approximately > > > every 2 minutes. In /var/log/messages I find the following: > > > > > > Aug 12 14:45:12 lina kernel: [ 2256.208621] wlp1s0: disconnect from > > > AP > > > xx:xx:xx:xx:xx:xx for new auth to yy:yy:yy:yy:yy:yy > > > Aug 12 14:45:12 lina kernel: [ 2256.213032] wlp1s0: authenticate > > > with > > > yy:yy:yy:yy:yy:yy > > > Aug 12 14:45:12 lina kernel: [ 2256.223163] wlp1s0: send auth to > > > yy:yy:yy:yy:yy:yy (try 1/3) > > > Aug 12 14:45:12 lina NetworkManager[564]: <info> [1534077912.6843] > > > device > > > (wlp1s0): supplicant interface state: completed -> authenticating > > > Aug 12 14:45:12 lina kernel: [ 2256.228342] wlp1s0: authenticated > > > Aug 12 14:45:12 lina kernel: [ 2256.229481] wlp1s0: associate with > > > yy:yy:yy:yy:yy:yy (try 1/3) > > > Aug 12 14:45:12 lina kernel: [ 2256.230627] wlp1s0: RX AssocResp > > > from > > > yy:yy:yy:yy:yy:yy (capab=0x11 status=0 aid=1) > > > Aug 12 14:45:12 lina kernel: [ 2256.231932] wlp1s0: associated > > > Aug 12 14:45:12 lina NetworkManager[564]: <info> [1534077912.6931] > > > device > > > (wlp1s0): supplicant interface state: authenticating -> associated > > > Aug 12 14:45:12 lina NetworkManager[564]: <info> [1534077912.7338] > > > device > > > (wlp1s0): supplicant interface state: associated -> 4-way handshake > > > Aug 12 14:45:12 lina NetworkManager[564]: <info> [1534077912.7414] > > > device > > > (wlp1s0): supplicant interface state: 4-way handshake -> completed > > > > > > where xx:xx:xx:xx:xx:xx the MAC of 2.4 and yy:yy:yy:yy:yy:yy the > > > MAC of 5 > > > GHz net is. > > > > > > However, this happens not at all places in my house. Near the > > > router, 5 > > > GHz is much stronger than 2.4 Ghz > > > and the system keeps th 5 GHz net. But in the living room, both > > > nets have > > > nearly the same strength and the > > > systems switches all the time. > > > > > > I found a lot of description of exactly this problem, but no > > > solution on > > > the net. See e.g. > > > https://forum.manjaro.org/t/frequent-wifi-disconnect/12211 > > > > > > https://jeremyfelt.com/2017/01/02/things-i-learned-or-broke-while-t > > > rying-to-fix-my-wireless-in-ubuntu-16-10/ > > > > > > https://www.archybold.com/blog/post/intermittent-connectionhigh-pac > > > ket-loss-intel-wireless-driver-iwlwifi-ubuntu-linux-networkmanager > > > > > > I think there should be some treshold that avoids switching between > > > nets > > > based on small fluctiations. But > > > where can I set this treshold. And is the switching caused by NM or > > > by the > > > driver? As the bugreports > > > mention different adapters, I think its not driver specific. > > > > > > Any hints welcome. > > > > > > juergen > > > > > > This is a long time nuisance of mine with NM and wpa-supplicant in > > > Linux. > > > > I just set the BSSID in NM to the MAC of the 5Ghz chip on the AP > > . This also keeps it from scanning into 2.4 and causing 10 seconds > > drop > > outs. > > > > Unfortunately, I do not think a better way exists in Linux, which is > > unfortunate for us desktop users. IMO, it is a major flaw that needs > > to be > > reworked ground up - it only happens on Linux (compared to MacOS and > > Windows on the same AP anyway - I have never run *BSD variants on a > > desktop > > machine). > > > > > > - > > Greg > > _______________________________________________ > > networkmanager-list mailing list > > [email protected] > > https://mail.gnome.org/mailman/listinfo/networkmanager-list > _______________________________________________ > networkmanager-list mailing list > [email protected] > https://mail.gnome.org/mailman/listinfo/networkmanager-list >
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