WIFI clients only joining the 2.4-GHz?

Marc Abaya · ‎10-13-2016

We have this small remote office using 2504 WLC (ver 8.0.115.0) and two AP2702I access points, both set-up for 802.11a/n/ac and 802.11 b/g/n. There are about 30+ wireless clients in there and all are connected to the b/g/n channel only. This has been going on I believe since it was installed a year ago. I just enabled Band Select today but I still don't see them switching to the 5-GHz.

Any ideas what is causing this? I will try to power-cycle the APs later tonight but I don't that has anything to do with it.

Thanks for the inputs.

Marc Abaya · ‎10-13-2016

I should also add that this is small office, so the distance between the APs and wireless clients shouldn't be much of a factor.

Leo Laohoo · ‎10-13-2016

Are you sure the wireless clients support 802.11a/n?

Post the complete output to the command "sh client detail <wireless client MAC address>". This output will determine if a wireless client can see 802.11a radio.

Marc Abaya · ‎10-14-2016

These clients are newer Mac and Windows laptops. Here's one of them:

Client MAC Address............................... 00:9a:cd:14:36:61
Client Username ................................. N/A
AP MAC Address................................... a8:9d:21:82:6e:d0

AP radio slot Id................................. 0
Client State..................................... Associated
Client User Group................................
Client NAC OOB State............................. Access
Wireless LAN Id.................................. 1
Wireless LAN Network Name (SSID).................
Wireless LAN Profile Name........................
Hotspot (802.11u)................................ Not Supported
BSSID............................................ a8:9d:21:82:6e:d0
Connected For ................................... 11692 secs
Channel.......................................... 1
IP Address....................................... 10.100.10.129
Gateway Address.................................. Unknown
Netmask.......................................... Unknown
IPv6 Address..................................... fe80::29a:cdff:fe14:3661
Association Id................................... 34
Authentication Algorithm......................... Open System
Reason Code...................................... 1
--More-- or (q)uit
Status Code...................................... 0
Session Timeout.................................. 0
Client CCX version............................... No CCX support
QoS Level........................................ Silver
Avg data Rate.................................... 0
Burst data Rate.................................. 0
Avg Real time data Rate.......................... 0
Burst Real Time data Rate........................ 0
802.1P Priority Tag.............................. disabled
CTS Security Group Tag........................... Not Applicable
KTS CAC Capability............................... No
WMM Support...................................... Enabled
APSD ACs....................................... BK BE VI VO
Power Save....................................... ON
Current Rate..................................... m15
Supported Rates.................................. 1.0,2.0,5.5,11.0,6.0,9.0,
............................................. 12.0,18.0,24.0,36.0,48.0,
............................................. 54.0
Mobility State................................... Local
Mobility Move Count.............................. 0
Security Policy Completed........................ Yes
Policy Manager State............................. RUN
Policy Manager Rule Created...................... Yes
--More-- or (q)uit
Audit Session ID................................. 0a640a0a0000b1ed580077c6
AAA Role Type.................................... none
Local Policy Applied............................. none
IPv4 ACL Name.................................... none
FlexConnect ACL Applied Status................... Unavailable
IPv4 ACL Applied Status.......................... Unavailable
IPv6 ACL Name.................................... none
IPv6 ACL Applied Status.......................... Unavailable
Layer2 ACL Name.................................. none
Layer2 ACL Applied Status........................ Unavailable
mDNS Status...................................... Enabled
mDNS Profile Name................................ default-mdns-profile
No. of mDNS Services Advertised.................. 0
Policy Type...................................... WPA2
Authentication Key Management.................... PSK
Encryption Cipher................................ CCMP (AES)
Protected Management Frame ...................... No
Management Frame Protection...................... No
EAP Type......................................... Unknown
Interface........................................ management
VLAN............................................. 0
Quarantine VLAN.................................. 0
Access VLAN...................................... 0
--More-- or (q)uit
Local Bridging VLAN.............................. 0
Client Capabilities:
CF Pollable................................ Not implemented
CF Poll Request............................ Not implemented
Short Preamble............................. Implemented
PBCC....................................... Not implemented
Channel Agility............................ Not implemented
Listen Interval............................ 10
Fast BSS Transition........................ Not implemented
Client Wifi Direct Capabilities:
WFD capable................................ No
Manged WFD capable......................... No
Cross Connection Capable................... No
Support Concurrent Operation............... No
Fast BSS Transition Details:
Client Statistics:
Number of Bytes Received................... 1857382
Number of Bytes Sent....................... 4700770
Total Number of Bytes Sent................. 4700770
Total Number of Bytes Recv................. 1857382
Number of Bytes Sent (last 90s)............ 0
Number of Bytes Recv (last 90s)............ 0
Number of Packets Received................. 8268
--More-- or (q)uit
Number of Packets Sent..................... 7622
Number of Interim-Update Sent.............. 0
Number of EAP Id Request Msg Timeouts...... 0
Number of EAP Id Request Msg Failures...... 0
Number of EAP Request Msg Timeouts......... 0
Number of EAP Request Msg Failures......... 0
Number of EAP Key Msg Timeouts............. 2
Number of EAP Key Msg Failures............. 0
Number of Data Retries..................... 5202
Number of RTS Retries...................... 0
Number of Duplicate Received Packets....... 507
Number of Decrypt Failed Packets........... 0
Number of Mic Failured Packets............. 0
Number of Mic Missing Packets.............. 0
Number of RA Packets Dropped............... 0
Number of Policy Errors.................... 0
Radio Signal Strength Indicator............ -53 dBm
Signal to Noise Ratio...................... 37 dB
Client Rate Limiting Statistics:
Number of Data Packets Received............ 0
Number of Data Rx Packets Dropped.......... 0
Number of Data Bytes Received.............. 0
Number of Data Rx Bytes Dropped............ 0
--More-- or (q)uit
Number of Realtime Packets Received........ 0
Number of Realtime Rx Packets Dropped...... 0
Number of Realtime Bytes Received.......... 0
Number of Realtime Rx Bytes Dropped........ 0
Number of Data Packets Sent................ 0
Number of Data Tx Packets Dropped.......... 0
Number of Data Bytes Sent.................. 0
Number of Data Tx Bytes Dropped............ 0
Number of Realtime Packets Sent............ 0
Number of Realtime Tx Packets Dropped...... 0
Number of Realtime Bytes Sent.............. 0
Number of Realtime Tx Bytes Dropped........ 0
Nearby AP Statistics:
(slot 0)
antenna0: 198 secs ago................... -72 dBm
antenna1: 198 secs ago................... -71 dBm
(slot 1)
antenna0: 197 secs ago................... -82 dBm
antenna1: 197 secs ago................... -75 dBm
(slot 0)
antenna0: 198 secs ago................... -55 dBm
antenna1: 198 secs ago................... -58 dBm
(slot 1)
--More-- or (q)uit
antenna0: 1333 secs ago.................. -56 dBm
antenna1: 1333 secs ago.................. -58 dBm
DNS Server details:
DNS server IP ............................. 0.0.0.0
DNS server IP ............................. 0.0.0.0
Assisted Roaming Prediction List details:
Client Dhcp Required: False
Allowed (URL)IP Addresses
-------------------------
AVC Profile Name: ............................... none

Leo Laohoo · ‎10-14-2016

Radio Signal Strength Indicator............ -53 dBm
Signal to Noise Ratio...................... 37 dB

This tells, from the "eyes" of the AP, what RSSI return it can see from the wireless client. Good signal.

antenna0: 198 secs ago................... -55 dBm
antenna1: 198 secs ago................... -58 dBm
(slot 1)
--More-- or (q)uit
antenna0: 1333 secs ago.................. -56 dBm
antenna1: 1333 secs ago.................. -58 dBm

This is telling me what nearby APs can "see" from the wireless client. Again, the signal is good, particularly 802.11a vs 802.11b radio.

It's a "tie". At the end of the day, the wireless client makes the ultimate decision which AP to join and which radio to use. I don't see any discrepancies at all.

Supported Rates.................................. 1.0,2.0,5.5,11.0,6.0,9.0,
............................................. 12.0,18.0,24.0,36.0,48.0,
............................................. 54.0

You might want to adjust the Data Rates of the 802.11b radio. Disable 802.11b data rates from 1- to 11 Mbps, make 12 Mbps "Mandatory" and the rest at "Supported". See if this helps.

Marc Abaya · ‎10-14-2016

Yes, have tried playing with the 802.11b rates also but with the same results. There are about 40+ wireless clients in this office, with a mix of iPhone, Mac, PC, Android, etc.. I don't understand why all of them will choose the 2.4GHz radio only. It can't be the client, right?

I have here a snippet of a "debug client" for one of the users in case you want to see:

*apfMsConnTask_0: Oct 14 14:17:31.187: 00:80:92:c8:a5:60 STA - rates (8): 2 4 11 150 36 48 200 108 12 146 152 96 0 0 0 0
*apfMsConnTask_0: Oct 14 14:17:31.187: 00:80:92:c8:a5:60 suppRates statusCode is 18 and gotSuppRatesElement is 0
*apfMsConnTask_0: Oct 14 14:17:31.187: 00:80:92:c8:a5:60 STA - rates (12): 2 4 11 150 36 48 200 108 12 146 152 96 0 0 0 0
*apfMsConnTask_0: Oct 14 14:17:31.187: 00:80:92:c8:a5:60 extSuppRates statusCode is 0 and gotExtSuppRatesElement is 1
*apfMsConnTask_0: Oct 14 14:17:31.187: RSNIE in Assoc. Req.: (20)

It's weird.

hypnotoad · ‎10-14-2016

The 2.4 frequency can cover a greater distance than 5g. It's likely that your clients are seeing and associating to 2.4g before they are within range of 5g. You can adjust data rates and power on the 2.4g to compensate but ultimately it's the client that makes the decision.

There are some client settings you can to to force or prefer 5g depending on OS and NIC vendor.

Do a site survey and see how far out your 2.4G is bleeding out as compared to the 5G.

You could turn off 2.4G completely and tell your users to upgrade their devices if they don't have 5G support. That is pretty harsh though.

--Patrick

Marc Abaya · ‎10-14-2016

I'm testing a user within 10 feet of the nearest AP. It can't be the distance. And from the RSSI measurement above, signal is within -50 dbm which is good.

Leo Laohoo · ‎10-14-2016

Try upgrading the firmware of the controller and see if there are any improvements.

Scott Fella · ‎10-14-2016

Here are a few things to try. Enable band select and configure band select globally from default of 2 to 6. Also lower the 2.4ghz max tx to at least 6dbi below the max of the 5ghz. For example, max tx on the 5ghz, set to 17dbm and on the 2.4ghz set to 11dbm.

Also verify that the 5ghz is working fine. On one of the Windows laptop, set the NIC to only use 5ghz and verify it connects. There are issues we have seen. It on the 3700's where the 5ghz stops servicing clients. A reboot fixes the issue.

-Scott

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-Scott
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Marc Abaya · ‎10-17-2016

As it turns-out, the APs installed are called "universal APs". The technician who installed this isn't aware. Now, we need to prime the APs for it to support 5-GHz, otherwise it will stay in scanner mode.

More info on this:

http://www.cisco.com/c/en/us/td/docs/wireless/access_point/ux-ap/guide/uxap-mobapp-g.html#pgfId-91287

This fixes my problem. Thanks for all the inputs.