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Network Problems of Auto Deployed ESXi Host in LAB

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I built a simple Auto Deploy environment by vSphere 6.5 on nested environment. I created virtual ESXi hosts on a physical ESXi host to do the testing. The whole configuration was smoothly, I’m impressed Auto Deploy can be implemented in few hours. One thing bothered me was networking.

New ESXi hosts cannot get IP addresses properly somehow. It’s not a single problem. The symptoms are ESXi hosts cannot get IP address, or the Configure Management Network was grayed out on console, or ESXi hosts can get IP address but no responding to ping. Just quick post my solutions here.

To fix all these problems you need to do following:

  1. Enable Promiscuous Mode on the vSwtich which is attached to nested ESXi hosts on physical ESXi hosts.
  2. (I did that on Web Client of vCenter 6.5 U1. You may see different procedure on earlier versions.) Edit the host profile of Auto Deploy — Networking configuration — Host port group — Highlight Management Network — The option Determine how MAC address for vmknic should be decided — Choose Use the MAC Address from which the system was PXE booted.

If you don’t do step 1, your nested ESXi hosts may not able to get DHCP IP addresses properly, or it can get IP addresses but maps to a new MAC address lead to network packages cannot be transmitted.

Nested ESXi hosts get a DHCP IP addresses when do PXE booting. The hosts get another new IP addresses when apply host profile as soon as management network is created. It could be two different IP addresses and the MAC address of management network could be a new one that not same to any of vmnics. It will be hard to trace back on network switch in real environment, so I think it’s better also to do step 2.

Update 10/25/2017 — You should choose “User must explicitly choose the policy option” in step 2 above if you have multiple NICs. The reason is DHCP IP address during PXE may be captured by random NICs. If you choose what I mentioned in step 2, you will see DHCP server may learns MAC address of a none management network NICs associated with management IP address. Please refer this article for more detail.