Cannot connect to one of many SSIDs on a AP

AP has multiple SSIDs but randomly cannot connect to one SSID. The device is trying to negotiate and authenticate but cannot receive an IP address from the AP.  This can cause due to DHCP pool of available IP addresses being exhausted and there are many conflicts. To resolve the issue:

• connect to the main switch at the site
• show run | section dhcp
• clear all conflicts: clear ip dhcp conflict *
• ip dhcp pool guest_wireless
• lease for 8 hours: lease 0 8
• end
• wr
• show interface counters errors 
  
  
  

Testing the Internet Speed via CLI

• Speed test: npm install -g speed-test
• to run: speed-test
• Fast.com: npm install -g fast-cli
• to run: fast -u
  
  
  

HCI - Calculating the Available Storage

 For calculating the available storage given a certain number of disks, nodes, and RF:

((disk-size * #disks * #nodes)/RF) * 0.92

OR 

((#disks * #nodes * disk size)*0.93(Metadata)*0.7(Storage Operating Threshold))/(RF(replication Factor)*0.63(Storage Optimization Gain))

How to fix Windows 11 update stuck at 0%, 61%, 99%, 100%

• Turn off Windows Update and Background Intelligent Transfer Service
• Open the Start menu search, type “cmd”, and then select the “Run as administrator” option to launch an elevated Command Prompt.
• Execute the command net stop wuauserv and net stop bits in order.
• Close Command prompt
• Delete the update files in the SoftwareDistribution folder
• Navigate to C:\Windows\SoftwareDistribution and select all the files and folders there.
• Right-click on the selected items and select Delete. If you fail to delete them, restart your computer and try again.
• Turn on the services again
• Launch Command Prompt in Admin mode. 
• Run the command net start wuauserv and net start bits one by one.
• Exit Command Prompt.

Setup TFT Server on Windows

• Download and install the free TFTP Server from SolarWind
• Configure the server 
• Push file to tftp server: tftp -i localhost put d:\123.img
• Pull file from tftp server: tftp -i localhost get 123.img d:\123.img
• Default tftp file location on disk: C:\TFTP-Root
• Visit here for more info

Find the Windows Product Key

PowerShell
powershell "(Get-WmiObject -query 'select * from SoftwareLicensingService').OA3xOriginalProductKey"

Command Prompt

wmic path softwareLicensingService get OA3xOriginalProductKey

Registry

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SoftwareProtectionPlatform

Unsupported Transceiver in Cisco Catalyst Switch Sub-module

All SFP modules contain a number of recorded values in their EEPROM and include

• Vendor Name
• Vendor ID
• Serial Number
• Security Code
• CRC

Force CISCO Switch to use 3rd Party SFPs

Despite the error displayed, which leaves no hope for a solution, keep smiling as you're about to be given one. There are two undocumented commands which can be used to force the Cisco Catalyst switch to enable the GBIC port and use the 3rd party SFP:

Host(config)# service unsupported-transceiver

Warning: When Cisco determines that a fault or defect can be traced to the use of third-party transceivers installed by a customer or reseller, then, at Cisco's discretion, Cisco may withhold support under warranty or a Cisco support program. In the course of providing support for a Cisco networking product, Cisco may require that the end user install Cisco transceivers if Cisco determines that removing third-party parts will assist Cisco in diagnosing the cause of a support issue.

Host(config)# no errdisable detect cause gbic-invalid