Can't turn 2.4Ghz off on MR53 and MR53E APs

pgrovesnz
Getting noticed

Can't turn 2.4Ghz off on MR53 and MR53E APs

Hi, I was wondering if anyone had tried to turn off 2.4GHz on MR53 or MR53E APs?

 

We have MR53E APs and applying a 5GHz only profile didn't turn off the 2.4GHz radio.

 

I found that there are no SSIDs being broadcast on the 2.4GHz but the 2.4GHz isn't turned off.

 

If I attempt to set the target power for 2.4GHz on an AP to Off, it goes to full power 29 dBm. If I monitor the AP from another AP I see that there are no SSIDs being broadcast, but see the power at -40dBm.

 

We are using firmware 26.2 as that was recommended by Meraki.

 

Is anyone able to try this in a test environment and see if they have the same issue? Meraki don't seem to have any other clients that have logged issues like this.

19 REPLIES 19
ww
Kind of a big deal
Kind of a big deal

does this work?

go to wireless》 access control. and set 5 GHz band only for each ssid that is active.   

 

can it be the dual band air marshall radio.

jdsilva
Kind of a big deal

How are you determining that 2.4 isn't being broadcast?

 

Do you have band steering enabled? That can "hide" 2.4, in a manner of speaking.

 

https://documentation.meraki.com/MR/Radio_Settings/Band_Steering_Overview

 

 

You are correct, that when you choose to manually/statically configure the AP (any model) to OFF, it does not actually turn it 'off' power wise.

It is still 'on', however it will not broadcast any of your SSID's, which at the end of the day is what you want.

What it will do however, is still keep broadcasting its MESHING frames..

Pretty sure the MESHING is at max power and 1 Mbps, the way Cisco RRM frames are as well, so even if you set the 2.4GHz power to 1 dBm, those MESHING frames will still send at max power + lowest data rate.

This is why you can still 'see it' from another AP. I would REALLY love for it to actually turn all the way off though. Really sucks that it doesn't.

The only way to turn off the MESHING (which should be the only traffic coming from it), is to have support give you access to enable/disable MESHING under the General settings for each Network.

However, I can tell you first hand that 26.X train has a very specific and particular bug with MESHING (in the release notes as known issue), so if you disable it, your access points will start rebooting randomly.

Nolan Herring | nolanwifi.com
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Thanks, that is the information that I need. Since, the network is being set up for a high density deployment I will ask for the ability to turn it off and see if I have issues.

Do you mean turn off MESHING?

If your running 26.X code I would not do it, as I know first hand it is going to cause issues with stability.

25.13 should be fine (as far as I know)
Nolan Herring | nolanwifi.com
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@NolanHerring wrote:
Do you mean turn off MESHING?

If your running 26.X code I would not do it, as I know first hand it is going to cause issues with stability.

25.13 should be fine (as far as I know)

Yes, I will go back to 25.13 and turn meshing off. Is there any need to have meshing enabled?

 

The wireless engineer that was tuning the network for high density, thought the behavior of the Meraki access points was extremely bad. Since he works with all other major access points I trust his assessment.


@NolanHerring wrote:

The only way to turn off the MESHING (which should be the only traffic coming from it), is to have support give you access to enable/disable MESHING under the General settings for each Network


We already have this turned off and are haven' any issues apart from the 2.4GHz at full power.

 

I will try firmware 25.13 with meshing turned off in a test network and see how it behaves.

Sounds good

What I will tell you is that with the 2.4GHZ radio 'OFF' and MESHING set to Disabled, the AP will still show the 2.4GHz radio power at whatever value it is going to randomly choose. So you'll just have to ignore that, and know that there isn't anything emitting from it.
Nolan Herring | nolanwifi.com
TwitterLinkedIn

 


@NolanHerring wrote:
Sounds good

What I will tell you is that with the 2.4GHZ radio 'OFF' and MESHING set to Disabled, the AP will still show the 2.4GHz radio power at whatever value it is going to randomly choose. So you'll just have to ignore that, and know that there isn't anything emitting from it.

If it does behave like that that is terrible behavior when tuning a network at a stadium environment.

 

We have 11 MR53E access points with narrow patch antennas. For the 2.4GHz to work better and avoid multiple APs on the same channel we want to completely disable the 2.4 on some APs (6 of them). The rest of the APs have the power level dropped to below 8.

 

Having any AP at full power will cause issues on the other APs using the same channel.

 

The only solution at the moment is to set the AP power on the APs to low and hopefully cause any other issues.


@pgrovesnz wrote:

 


@NolanHerring wrote:
Sounds good

What I will tell you is that with the 2.4GHZ radio 'OFF' and MESHING set to Disabled, the AP will still show the 2.4GHz radio power at whatever value it is going to randomly choose. So you'll just have to ignore that, and know that there isn't anything emitting from it.

If it does behave like that that is terrible behavior when tuning a network at a stadium environment.

 

We have 11 MR53E access points with narrow patch antennas. For the 2.4GHz to work better and avoid multiple APs on the same channel we want to completely disable the 2.4 on some APs (6 of them). The rest of the APs have the power level dropped to below 8.

 

Having any AP at full power will cause issues on the other APs using the same channel.

 

The only solution at the moment is to set the AP power on the APs to low and hopefully cause any other issues.


Wait, hold on a minute I think there is some confusion here.

 

You are correct you will want to disable some, but it is going to be truly impossible to eliminate any CCI/CCC on 2.4GHz. If your still using that band, it will be better to have 'some contention and full coverage', vs 'no contention and poor coverage'.

 

Your concerned that when you set them to OFF, that the power output value changes on the dashboard from lets say you had 8dBm, to 23dBm.  That happens when I turn it to OFF. You can safely ignore this.

 

They are indeed 'OFF' in the sense that they will not be broadcasting any wireless from your configured SSIDs. So you would be much better off turning those 6 that you want to disable into the OFF mode versus low power.  Low power means that they will indeed still be on and broadcasting and you don't want that if your trying to tune things.

 

Set them to OFF, they won't send any more traffic, and ignore that silly default dBm value you see on the dashboard.

 

MESHING is going to be there if you set to OFF or low power. It will be there at max power and lowest data rate no matter what setting you use. Just like Cisco's RRM, this can't be edited. The only way to stop that is to disable meshing all together.

 

So your best solution is to use 25.13, disable meshing, and turn off those 6 access point 2.4GHz radios, and you'll be golden as far as trying to accomplish what you are trying to do.  Insert any vendor and you'll end up in the same end state. Meraki just takes a little more tweaking to maneuver into that position (calling support etc.).

Nolan Herring | nolanwifi.com
TwitterLinkedIn

yoda11111.jpg

Nolan Herring | nolanwifi.com
TwitterLinkedIn

I understand what you say, but if you use a wireless analyser to check the channel, you will see that the channel/s are flooded and will affect any access point and client using the channel.

 

Any device sending traffic on a channel will cause retransmissions on the channel. When there is a high density of devices the problem multiplies with clients waiting to transmit. If one device transmits at a slow rate that will cause all other devices to also transmit at a low rate.

 

Behaviour of the Meraki APs don't reflect best practise and stop you from tuning the network for best practise.

GIdenJoe
Kind of a big deal
Kind of a big deal

I have turned off the 2.4 GHz on a MR53 using RF profile where only 5 GHz band is allowed.

When I look at RF spectrum from neighboring AP's I can still see the MAC address of the disabled AP broadcasting quite strong but at 802.11g mode on channel 1 but at a high data rate (I don't trust that output because it sees 802.11ac on channel 1???)

So I started a packet capture on the neighboring AP and found it that it still sends some LLC frames once every 30 seconds.
Capture-AP.PNG

@GIdenJoe Is that with MESHING enabled or disabled? Probably meshing is what your still seeing being sent as it will keep sending those frames to ensure the AP can still work in repeater mode.

Nolan Herring | nolanwifi.com
TwitterLinkedIn

Hey @NolanHerring, the option to disable meshing is not available by default. So in that environment it's still running.
Btw I found your fun 2 year old article about this which I agree with fully:

https://nolanwifi.com/2017/02/06/merakis-mesh-mess/


@NolanHerring wrote:

@GIdenJoe Is that with MESHING enabled or disabled? Probably meshing is what your still seeing being sent as it will keep sending those frames to ensure the AP can still work in repeater mode.


We had already turned off meshing. We had an issue with a few access points going into the repeater mode instead of using their wired network connection, so turned it off.

 

It seems that turning off mesh mode stops access points going into repeater mode but the radio still seems to send frames.

I can monitor it from the adjacent access points
pgrovesnz
Getting noticed

Since the wireless is being set up for a high density deployment we still want 2.4GHz available on some access points so this isn't an option.


@pgrovesnz wrote:
Since the wireless is being set up for a high density deployment we still want 2.4GHz available on some access points so this isn't an option.

@pgrovesnz wrote:
I can monitor it from the adjacent access points

 

That is fine. If your SSID is set for dual-band, it will still function on the access points that you leave 2.4GHz enabled. The ones that you have set the 2.4GHz radio to OFF, simply will not broadcast the SSID on the 2.4GHz radio, even if it is set for dual-band.

 

You can monitor it from adjacent access points because MESHING is what is being used for that. It is not broadcasting your SSID on the 2.4GHz radio.

Nolan Herring | nolanwifi.com
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