In this article I will demonstrate how to easily update ESXi 6.5 using Update Manager.
In this demonstration I will use vCenter Update Manager, so I must have the proper vCenter version already installed. As a rule of thumb, you always need to update vCenter Server before ESXi (vSphere). Update process for VMware solutions can be tricky, so for specific order update for VMware products I suggest you to check KB2147289.
Note: If you look for VCSA update instructions, check this article: How to Update vCenter Server Appliance to 6.5 Update 1b.
Check vCenter and ESXi versions
I will connect to my vCenter Server using vSphere Web Client and I will check the vCenter version. As you can see below, I am running vCenter version 6.5.0, build 6816762, which is the latest version at the moment I am writing this article.
Next, I will check ESXi version. I navigate in the left panel to the ESXi server I plan to update (esx1.lab.local). In the right panel, I can see the installed product: VMware ESXi 6.5.0 build 5310536.
I will use now my.vmware.com site.to find the latest version for ESXi 6.5. As you can see below, latest build is 6765664. Take note of the Bulletin Number, we will use it later: ESXi650-201710401-BG.