The following is an excerpt from my book Mastering VMware vSphere 5.5, which you can read more on this blog over the coming weeks. To read the full text you can get a copy here. To test out this procedure, download AutoLab.
During the installation of ESXi, the installer creates a virtual switch—also known as a vSwitch— bound to a physical NIC. The tricky part, depending on your server hardware, is that the installer might select a different physical NIC than the one you need for correct network connectivity. Consider the scenario depicted in Figure 2.12. If, for whatever reason, the ESXi installer doesn’t link the correct physical NIC to the vSwitch it creates, then you won’t have network connectivity to that host. We’ll talk more about why ESXi’s network connectivity must be configured with the correct NIC in Chapter 5, but for now just understand that this is a requirement for connectivity. Since you need network connectivity to manage the host from the vSphere Client, how do you fix this?
The simplest fix for this problem is to unplug the network cable from the current Ethernet port in the back of the server and continue trying the remaining ports until the host is accessible, but that’s not always possible or desirable. The better way is to use the DCUI to reconfigure the management network so that it is converted the way you need it to be configured.
Perform the following steps to fix the management NIC in ESXi using the DCUI:
- Access the console of the ESXi host, either physically or via a remote console solution such as an IP-based KVM.
- On the ESXi home screen, shown in Figure 2.13, press F2 for Customize System/View Logs. If a root password has been set, enter that root password.
- From the System Customization menu, select Configure Management Network, and press Enter.
- From the Configure Management Network menu, select Network Adapters, and press Enter.
- Use the spacebar to toggle which network adapter or adapters will be used for the system’s management network, as shown in Figure 2.14. Press Enter when finished.
- Press Esc to exit the Configure Management Network menu. When prompted to apply changes and restart the management network, press Y. After the correct NIC has been assigned to the ESXi management network, the System Customization menu provides a Test Management Network option to verify network connectivity.
- Press Esc to log out of the System Customization menu and return to the ESXi home screen.
The other options within the DCUI for troubleshooting management network issues are covered in detail within Chapter 5.
At this point, you should have management network connectivity to the ESXi host, and from here forward you can use the vSphere Client to perform other configuration tasks, such as configuring time synchronization and name resolution.