For troubleshooting purposes, users may need to access the ESXi Direct Console User Interface (DCUI), either remotely through an out-of-band system like an iDRAC or iLO, or directly from the physical server.
For auditing purposes, all login methods to ESXi (SSH, API, Host Client, and DCUI) are recorded, and a corresponding vSphere Event called UserLoginSessionEvent is generated for easy filtering.
I recently shared my VMware Cloud Foundation (VCF) 9.0 Mini Rack build, which includes the use of a tiny 7" LCD screen for direct console access to the ESX hosts. Since the LCD is optimizing for the 10" inch rack, it is also using a non-standard resolution of 1280x400, which can make the output pretty compressed as you can see from the ESX DCUI screen.
This is definitely a niche use case, but I was curious if we had any workarounds that could be used to improve the screen resolution, especially handling large amounts of text when going into the ESX Shell 🤔
While installing the ESXi 7.0 Update 1 on one of my physical system, I happened to be in the "Configure Management Network" section of the ESXi Direct Console UI (DCUI) and noticed something I had never seen before. As shown in the screenshot, it now shows the IP Address of the DHCP server in which ESXi received the DHCP lease.
I had not noticed this before and after asking on Twitter, it looks like this is definitely a new enhancement that was added fairly recently. I did not see this in one of my ESXi 6.7 Update 3 deployments, but it may have came in a later patch but definitely new in ESXi 7.0 or greater. Not only is this a quick and easy way to identify the DHCP server being used but in case you need to track down an unexpected rogue DHCP server running, this will certainly come in handy as pointed out by John.
Trying to get rogue DHCP servers under control?
Remember kids, DHCP Snooping saves lives! https://t.co/FKPgKzI9In— ⍼ John Nicholson ⍼ (@Lost_Signal) November 20, 2020