Hi,

Does it show the NIC from the CMC or BIOS? Which NDC are you using? Are you able to try the blade in a different slot on the chassis?

Hi, my Google search got me to this forum posting. You ever find out the problem?

One of our M620 blades suddenly lost its NICs after a reboot. OS: XenServer 6.5, was in server pool with 4 other M620 servers.

Motherboard replaced, one mezzanine card replaced, moved to different slot in M1000e enclosure. Updated iDRAC firmware 2.50.50.50, NIC firmware, BIOS 2.5.4. Reinstalled OS twice. Used different network cables and switch ports.

Finally, the odd mezzanine error messages about changes went away. “Replaced part detected for device: mentioned both mezzanine cards”

Seemed stable enough to add back to server pool. Half the NICs showed disconnected afterwards. Took the server out of the XenServer pool again.

Reinstalled OS again, this time using XenServer 7.2. First boot, the OS could not show the NIC numbers and all disconnected. Only access via iDRAC console. Used the emergency network reset. The server finally showed all of the NICs and the correct ones connected. It also shows a bunch of odd pool-wide NICs. This latest build was never in a server pool. Is the hardware keeping bad cache somehow? Dell technician suggested turning off FlexAddress. Will do that and rebuild the OS again.

Follow-up, the server's NICs are fine now after disabling FlexAddress on the enclosure slot.  I will disable that setting when I reinstall the OS on other blades in the future. 

Hi,

Thanks for the info on Flexaddressing.