When working with installers or firmware for firewalls, switches, hypervisors etc it is very important that you verify the integrity of the downloaded file in case it has been corrupted in transit to ensure it does not contain errors when running the install.

Fortunately, this can be simply and quickly checked using a Powershell command against the file and specifying the Algorithm.

A VMware example of checksums against different hashes is shown below which is given on the download section of an ISO

You only need to run a check on 1 hash algorithm but I have included the commands for the 3 most common ones to use against your ISO/File and the hash outcome should match what is shown on the vendors website. If the hashes do not match there is corruption in the file, and it should be downloaded again ideally using a download manager rather than through the browser. Do not install firmware if the hashes do not match up as you could end up with an expensive brick on your hands.

Get-FileHash C:\Temp\VMwareESXi67.iso -Algorithm MD5

Get-FileHash C:\Temp\VMwareESXi67.iso -Algorithm SHA1

Get-FileHash C:\Temp\VMwareESXi67.iso -Algorithm SHA256

If you compare the VMware hashes in the image above with those shown below which have been ran against the downloaded ISO you can see they are identical which proves that the integrity of the file and means you can have the confidence in the ISO when running your upgrade/install.