I am constantly getting the below coverage hole alert, the AP is used to cover a warehouse area, sometimes the users will carry their notebook out of the warehouse and back in. The radio frequency is set to auto. What could be the cause of this issue?
An Alert of Category Coverage Hole is generated with severity 3 by Radio KM3_Ship_AP01/1 .
The message of the alert is AP 'KM3_Ship_AP01', interface '802.11b/g' on Controller '10.16.14.3'. Coverage threshold of '12' violated. Total no of clients is '3' and no of failed clients is '2'. Worst signal quality experienced by client='00:19:7d:1e:41:f3' RSSI='-65' dBm SNR='-116', client='00:19:7d:18:12:d6' RSSI='-68' dBm SNR='-65'..
If you have users walking out of the Warehouse I would expect you to see these alerts. Here is some info on what causes the "Coverage Hole" alerts;
Coverage Hole Detection and Correction
If clients on a lightweight access point are detected at signal-to-noise ratio (SNR) levels that are lower than the thresholds specified in the Auto RF configuration, the access point sends a "coverage hole" alert to the controller. The alert indicates the existence of an area where clients are continually experiencing poor signal coverage, without having a viable access point to which to roam.
The Coverage Hole Detection and Correction algorithm is primarily aimed at the determination of coverage holes based on the quality of client signal levels.
The algorithm determines if a coverage hole exists when the clients' SNR levels pass below a given SNR threshold. The SNR threshold is considered on an individual AP basis and is based primarily on each AP's transmit power level. The higher the AP power levels, the more noise the APs tolerate as compared to the client signal strength, which means a lower tolerated SNR value.
This SNR threshold varies based on two values: the AP transmit power and the controller Coverage profile value. The threshold is defined by the transmit power (represented in dBm) of each AP, minus the constant value of 17dBm, minus the user-configurable Coverage profile value. The Coverage value is defaulted to 12 dB. The client SNR threshold value is the absolute value, or the positive number, that results from this equation:
Coverage Hole SNR Threshold Equation:
Client SNR Cutoff Value (|dB|) = [AP Transmit Power (dBm) ? Constant (17 dBm) ? Coverage Profile (dB)]
Once the average SNR of a single client dips below this SNR threshold for at least 60 seconds, the AP transmit power of that client is increased to the appropriate level in order to mitigate the SNR violation, and correct the coverage hole. Only one client need violate this threshold in order to trigger a correction.
Each controller runs the Coverage Hole Detection and Correction algorithm for each radio on each of its APs every three minutes. The default value of 180 seconds can be changed, as described in the Monitor Intervals (60 to 3600 secs) section of this document.
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...