Summary: How to access the Tech Support Mode on ESXi 5.1.
Date: Around 2013
Refactor: 21 February 2025: Checked links and formatting.

When switching from ESX to ESXi one of the bigger downsides is the lack of the Service Console. There is however a basic commandline option on the console which you can use for troubleshooting. Of course, for accessing this commandline you need either physical access to the host, or access to the host through a remote access card. We use IBM xSeries, so a IMM (Integrated Management Module) is what we'll use for this. First just access the console and unlock it by pressing F2 and provinding the root credentials. Then use the keyboard to access the menu item “Troubleshooting Mode Options”. Here you can do all sort of things, but now we need to enable the ESXi Shell by selecting the option and pressing ENTER. When done you'll see a notice on the right side telling you the shell is enabled:

Then to access the shell you'll need to press ALT+F1 at the same time. Now that might be hard using an IMM so use the menu option to send the key combination to the server:

Now you'll see a login prompt where you can enter the root credentials again, and then issue, for example, a command to add a route to a specific host:

For reference, this is the command example so you can copy it:

esxcfg-route -a 192.168.100.0/24 192.168.0.1
esxcfg-route -a 192.168.100.0 255.255.255.0 192.168.0.1