I've recently started testing the vSphere/ESXi 4 platforms and found something interesting.
The setup in question is as follows:
ESXi 4, build 164009
Dell PE2950 (first generation)
16GB RAM
Dual 5130 CPUs
Integrated Broadcom 5708 gigabit NICs
PCIe Dual port Intel PRO/1000 PT card
(storage is irrelevant at this point)
Foundry FLS 648 switch
Using this configuration, network connectivity is sporradic at first, and then just fails while using the on-board Broadcom NICs for the Management network. Looking at the switch we see some multiple spanning tree errors, and the port shuts down. Resetting the management network restores connectivity briefly, before the same thing starts all over again.
The same configuration works fine with ESX/ESXi 3.5.
The same configuration in a Cisco 3500 series switch also works fine.
If I flip the management network to run on the PCIe Intel NIC things work fine on either switch, so there must be some issue between the Broadcom 5708 and the Foundry switch. I've not been able to find any other information on this issue yet with lots of Googling, and wanted to post up and see if anyone else had experienced anything similar.
