802.11ac adapter randomly connecting using 802.11n protocol
We are testing out 802.11ac using a single Cisco 2702i WAP connected to our Cisco 5508 WLC. Everything is configured and we're getting 802.11ac speeds for our few 802.11ac client devices. However the issue is that sometimes client devices are connecting using 802.11n--the client's are connected at 2.4 GHz and 802.11n speeds (~144 Mbps) instead of 5 GHz.
Hardware involved include: 1 x Cisco 5508 WLC (running 220.127.116.11) and 1 x Cisco 2702i WAP. Client devices include one tablet and one laptop (both have 802.11ac adapters).
I have implemented the Band Select option for the wireless network, but still clients will still sometimes randomly connect using the 802.11n protocol instead of the 802.11ac they are capable of. When it connects using 802.11n, you just have to disconnect from the wireless and wait a few seconds before reconnecting to the wireless. Most of the times, you should then get 802.11ac speeds; sometimes you have to disconnect again.
Any suggestions on why this is happening and how to fix it? One option would be to disable the 2.4 GHz radio, either globally or for the specific WLAN, but I prefer not to because I want to retain backwards compatibility for older wireless clients if possible.
So in 80MHz, if you want to get MCS8-9 data rates you should have SNR of 35 or higher. If your clients are moving away from AP, then it is normal to change the modulation scheme & data rate per the RSSI & SNR.
Regarding client preferring 2.4GHz, you can simply disable low data rates 1,2,5.5,6,9,11Mpbs & make 12Mbps mandatory with other rates are supported in 802.11b/g/n band. If you have dense AP deployment further you can disable 12,18 Mbps & make 24Mbps mandatory & other rates as supported.
I'm sorry, but I probably was not very clear in my concern. I'm not really concerned about the wireless speed per se. Instead, my problem is the following: My 802.11ac client computers will randomly connect to a 802.11ac WAP using the 802.11n protocol.
I can confirm on both the WLC's Monitor tab and in Windows that the client is using its 802.11n radio in the 2.4 GHz range (instead of its 802.11ac radio in the 5 GHz range). BTW, in Windows, you can see this by using the "netsh wlan show interface" command.
I'm not sure, but I don't see how disabling the slower data rates for the 2.4 GHz radio will help because the clients should be connecting via 802.11ac which is 5 GHz only.
I think I now understand what you're saying with the data rates.....setting higher minimum-level requirements to join the network will make the 2.4 GHz band less appealing than the 5 GHz band. It's an interesting idea--I'll have to play around with it later.
We have two different models of computers that support 802.11ac: one model doesn't have the "Preferred Band" options under the wireless adapter's driver settings, but the other model of laptop does have that setting (as a side note, that laptop model has the exact same wireless adapter as the one in your screenshot). We'll use this setting to help steer devices to the correct band. For devices that don't have the "Preferred Band" option, the next paragraph will explain our workaround.
After some discussion with a coworker, I think we're going to use only the 5 GHz band for our internal users (since we can ensure the hardware supports 5 GHz). For the guest wireless network, we're going to limit that to only the 2.4 GHz band--this gives more compatibility for different devices that may not have 5 GHz radios (i.e. many smartphones).....and as an added bonus, it'll limit the speed of guest devices (to help prevent guests from using up all of our WAN bandwidth).
I think we're going to use only the 5 GHz band for our internal users
If you can do this, it is the best option in order to get better performance for your wireless clients.
For the guest wireless network, we're going to limit that to only the 2.4 GHz band--this gives more compatibility for different devices that may not have 5 GHz radios (i.e. many smartphones)
If you really do not want to give a better service for Guest users you can limit them to 2.4GHz. I would do it in a different way. I would allow both 2.4GHz/5.GHz for Guest SSID, but I would disable WMM under QoS tab. This will effectively block them getting 802.11n data rates while allowing them to connect in both 5GHz & 2.4GHz. (as much as possible get away from 2.4GHz)
As a side note, if you are using that AC7260 wireless NIC,then be aware those NIC drivers had some serious issue of not giving true 802.11ac performance. So if you are doing some performance test, you will see this. Make sure you go with the latest drivers for this NIC. Refer below for the performance I got with this NIC compare to other 802.11ac capable of devices.
Transferring Crash file from standby:
Login to the Active WLC in HA.
(Cisco Controller) >transfer upload datatype crash
(Cisco Controller) >transfer upload filename <Desired filename>
(Cisco Controller) >transfer up...
This is the start of a display filter cross reference between Wireshark and OmniPeek.
The 1st installment is a table of advanced filters. More filters will be added as time allows.
It is a living doc, so check back for changes every so often
Please feel ...
I have created a Powershell script to automatically add a Wireless Guest User on Cisco WLCs. (tested on 2500 Series)
The script should be completely self explanatory.
Powershell SNMP Module (Install-Module -Name SNMP)
SNMP Write Access to...