Physical Adapter in stand by mode?

Hi,

I am running vSphere Server version 5.1.0 (build 799731).

All of my ESXi hosts have the version 5.1.0, 799733.

I have noticed that on some on my ESXi hosts, one of the Physical Adapter to the vMotion on the VMkernel Port, is in stand by mode, but the other physical adapter is in normal mode.

I have attached a screendump of the issue.

Can you help me explain this?

Kind regards,

Carl-Marius