Wireless Client Count Lower Than Actual on Cisco Catalyst 9800 Controllers Using FlexConnect Local Switching

WhatsUp Gold may report significantly fewer wireless clients than are actually connected to a Cisco Catalyst 9800 Wireless LAN Controller when FlexConnect Local Switching is enabled. Analysis confirmed that all client records are successfully collected through SNMP; however, valid clients reporting zero transmit and receive byte counters are incorrectly excluded during processing, resulting in an underreported wireless client count.

Aug 6, 2026
Knowledge

Title

URL Name

wireless-client-count-lower-than-actual-on-cisco-catalyst-9800-controllers-using-flexconnect-local-switching

Article Number

000303764

Environment

WhatsUp Gold 2026.x Cisco Catalyst 9800 Wireless LAN Controller SNMPv3 authentication and privacy (authPriv) polling configured between WhatsUp Gold and the WLC Wireless access points configured for FlexConnect Local Switching

Question/Problem Description

The default out-of-the-box System Summary widget's wireless Client Count is significantly undercounting active clients compared to the actual number of clients on the WLC.

Observed discrepancy (same WLC, same day):
- 08:40 AM: WUG System Summary Clients = 948 | WLC's own reported client count = 2015
- ~2 hour later: WUG System Summary Clients = 1253 | WLC's own reported client count = 2404

WUG is consistently reporting roughly 47-52% of the actual client count, on two samples taken about an hour apart with different absolute client loads.

Steps to Reproduce

Clarifying Information

Verification

The analysis confirmed:

WhatsUp Gold successfully receives all client rows from the WLC during SNMP collection.
The issue is not caused by incomplete SNMP walks.
The issue is not related to SNMPv3 communication, polling failures, context configuration, or AP group partitioning.
Wireless clients are excluded only after the collection data is processed by the wireless collector logic.

Error Message

Defect Number

WUG-20525

Enhancement Number

Cause

The wireless collectors contain logic that discards client records when both of the following SNMP statistics are zero:

bsnMobileStationBytesReceived
bsnMobileStationBytesSent

On Cisco Catalyst 9800 controllers using FlexConnect Local Switching, zero-byte counters represent valid client records rather than invalid data. This results in legitimate wireless clients being omitted from the final client count.

Resolution

A software defect has been logged with Engineering:

Engineering is investigating a modification to the wireless collection logic so valid FlexConnect Local Switching clients are included in the reported wireless client totals.

Confirm whether the affected APs are configured for FlexConnect Local Switching on the Cisco Catalyst 9800 controller. Environments using this configuration are most likely to experience the discrepancy.

As a validation step, compare:

Wireless client totals reported by the controller.
Results from a direct SNMP walk of the wireless client tables.
Wireless client totals displayed within WhatsUp Gold.

If the controller and SNMP walk counts align while WhatsUp Gold reports fewer clients, the environment is likely affected by WUG-20525.

Workaround

Notes

Keyword Phrase

Last Modified Date

8/6/2026 1:19 PM