Disabling b/g, but not N (2.4)

[s.hellman]

I want to disable B and G, but not N (2.4) yet.

On the controller, Wireless / 80211b/g/n / Network, I can disable/enable "80211b/g Network status", will that disable the whole 2.4 radio, N also ?

If so, is there any other way of doing this, or should I just simply disable all the data rates of b/g ?

[Leo Laohoo]

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@s.hellman wrote:

I want to disable B and G, but not N (2.4) yet.

On the controller, Wireless / 80211b/g/n / Network, I can disable/enable "80211b/g Network status", will that disable the whole 2.4 radio, N also ?

If so, is there any other way of doing this, or should I just simply disable all the data rates of b/g ?

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In controller-based, there is no such thing as "b/g/n".  This is just sales talk.  It is "802.11b/g" and/or "802.11a/n/ac".  It is only 802.11a radio that is capable of 40 Mhz channel bonding to form "n".  

[s.hellman]

So.. unchecking the "802.11b/g Network status", I will still have 2.4 N ?

[Leo Laohoo]

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@s.hellman wrote:
So.. unchecking the "802.11b/g Network status", I will still have 2.4 N ?

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Whether you check or uncheck "802.11b/g Network Status" you WILL NOT HAVE 802.11n on the 2.4 Ghz radio.  

802.11n is only possible if you channel bond 5.0 Ghz.

[s.hellman]

OK

But I get confused when Prime report some clients using Protocol 802.11n(2.4GHz) and others using Protocol 802.11n(5GHz)

Why is it so?

[Scott Fella]

Just to add... you only really want to disable 802.11b and leave g & n on the 2.4ghz. There is no option to disable g.  Now on the 5ghz, there is a/n/ac which is not configurable. When you see a client as 802.11n on either band, it's because they either don't support ac on 5ghz or that they negotiated at 'N' rate. Get some old devices to test with and you will be able to understand better. Remember, it's what the client and AP negotiate at and 'N' can't be turned off.

-Scott 

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[s.hellman]

First you say: you WILL NOT HAVE 802.11n on the 2.4 Ghz radio...
Then: ..leave g & n on the 2.4ghz
I clearly see clients negotiated N on 2.4, and 2.4 N is supported by the standard.
The reason that we are considering disable both B and G, is that it was recomended if possible, by Cisco at last Cisco Live.
They also, ofcourse, recomended if possible to turn of 2.4 and only use 5, but that is not possible for us yet, since we still have clients that manage N but only at 2.4.
Not sure though about the gain of disable G, instead of disable data rates up to, say 24 or 36Mb ?

[Leo Laohoo]

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@s.hellman wrote:
The reason that we are considering disable both B and G, is that it was recomended if possible, by Cisco at last Cisco Live.

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I've been to Cisco Live several times and I've never seen any slides or any presentations recommending 802.11 b AND g to be disabled.  Slides and presentation will recommend 802.11b data rates to be disabled and leave the 802.11g data rates alone.  

Even the deployment guide for the 7925 & 8821 have never mentioned about disabling both.

[Scott Fella]

I didn't say that.  You can have 802.11n on 2.4ghz. Also at Cisco Live, they and a lot of others recommend to disable 802.11b in their environments as long as you don't have any old legacy device. You are mistaken about disabling b and g because you can only disable b.  When people say to disable b and g, then mean disable 2.4ghz all together.

To recap, 802.11n is supported on clients on 2.4ghz and 5ghz.  You cannot disable g or n.  You can only disable 802.11b by disabling all data rates from 1mbps to 11mbps.

-Scott 

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[s.hellman]

Yes,the slides says disable b, but the presenters talked about that it is time to also disable g, and also leave 2.4. I might have misunderstood this and that they meant leave 2.4 in both cases, even if it didn´t sound like that.
So, we will leave g as it is, and focus on cleaning out the only 2.4 devices, and then shut down 2.4
Back to my original question, yes disable "80211b/g Network status", disables the whole 2.4 radio

[Scott Fella]

Yes, if you disable 802.11b/g it disables 2.4ghz.  When people talk about disabling b, typically it disabling data rates or changing the radio policies in the wlan. Again, there is no way to disable g.

[patoberli]

To add a little theory.

All 2.4 GHz clients REQUIRE the 802.11g rates (besides the very old 11b ones) to be enabled to actually see the BSSID broadcasts. The frames which include the name of the BSSID and it's properties (enabled speeds, capabilities, encryption) will always be sent by the highest "required"rate, if I'm not mistaken. If you disable all rates, those frames won't anymore be sent and all BSSIDs will be "offline" on the 2.4 GHz.

What they talked about on the Cisco Live was, that it's about time that a new Wi-Fi standard will remove this requirement for the old legacy rates (the same is actually with the 802.11a rates) and use much faster rates for the BSSID announcements and stuff. This has still to be engineered and will probably take several more years until it's available.

[Scott Fella]

Well I guess we shall see if this gets incorporated as a standard for all vendors. I read your post as "disable b and g"today, which is not possible.