Issue with jumbo frames after upgrading nested ESXi servers in the lab to 5.5 and fix

IMPORTANT UPDATE AT THE END OF THE ARTICLE

In my lab I use to test and play with numerous VMware solutions, I have several nested ESXi servers running. Nested ESXi servers are ESXi servers running as a VM. This is a not supported option, but it does help me to test and play around with software without having to rebuild my physical lab environment all the time.

So first a little on the setup of my nested ESXi servers

The VM’s for my nested ESXI servers have 4 NIC’s

The first NIC connects to “vESXi Trunk” This is a port group on my physical ESXi hosts that is configured on a vDS with VLAN type “VLAN Trunking” so I get all VLAN’s in my nested ESXi host:

Screen Shot 2013-11-25 at 20.49.39

I use this VLAN trunk to present my management network and my VM networks to my nested ESXi servers

I also have a NIC that connects to my vMotion network, and two nice that connect to my iSCSI networks. I use two subnets and two VLAN’s for my iSCSI connections.

Screen Shot 2013-11-25 at 20.54.20

In my physical setup I use jumbo frames in these networks, and I did the same in my nested ESXi hosts, and it worked perfectly … Until I upgraded my nested ESXi hosts to vSphere 5.5 … Continue reading