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LOM Mapping in VCEM and NIC enumeration in ESXi

Occasional Visitor

LOM Mapping in VCEM and NIC enumeration in ESXi

My apologies if this is covered elsewhere but I've searched and can't seem to find my specific problem. Here's what's going on.


2 new C7000 chassis

4 new BL620c G7 blades

Flex-10s in each chassis


ESXi 5.5


All the controllers, blades, & interconnects have the same firmware.


Since these are full height blades they have 4 LOMs, e.g. two in slot 1 and two in slot 9. I believe that's correct. I had no problems setting up the first chassis. Created a VC domain, connected it to VCEM, defined my Shared Uplink Sets and networks and everything is good. I created a server profile with 4 Ethernet Network Connections. I don't get to pick the mapping though. I just assign it to the server and it shows up as...


LOM: 1-a => Bay 1:d9:v1

LOM: 2-a => Bay 2:d9:v1

LOM: 3-a => Bay 1:d1:v1

LOM: 4-a => Bay 1:d1:v1


I presumed that was correct, i.e. the first FlexNIC for each LOM.

On my blade I installed ESXi 5.5 and it identified 16 NICs of which 4 were connected:







Again, this seemingly made sense to me. I was basically equating it as:


vmnic0 = LOM: 1-a

vmnic1 = LOM: 2-a

vmnic2 = LOM: 3-a

vmnic3 = LOM: 4-a


So vmnic0 and vmnic2 are on the "A" side Flex-10 (left viewed from the back) and vmnic1 and vmnic3 are on the "B" side Flex-10 (right viewed from the back)


This worked perfectly. Hosts talked on the net. Trunking was gerat. I could create VMs. Even used a distributed virtual switch.


The problem came along when setting up the two blades in the second chassis. They are setup identically to the first two however for some strange reason they always enumerate the connected NICs as:







And I cannot understand why. In fact, the more I read the more confused I get. Looking at the info in the Onboard Administrator is even more confusing. It says:


Server NIC Information

  FlexFabric Embedded Ethernet

    Ethernet FlexNIC (NIC1) LOM:1-a

                      FFCoE FlexHBA LOM:1-b

    Ethernet FlexNIC (NIC5) LOM:1-c

    Ethernet FlexNIC (NIC7) LOM:1-d

    Ethernet FlexNIC (NIC2) LOM:2-a

                        FCoE FlexHBA  LOM:2-b

    Ethernet FlexNIC (NIC6) LOM:2-c

    Ethernet FlexNIC (NIC8) LOM:2-d

    Ethernet FlexNIC (NIC9) LOM:3-a

    Ethernet FlexNIC (NIC11) LOM:3-b

    Ethernet FlexNIC (NIC13) LOM:3-c

    Ethernet FlexNIC (NIC15) LOM:3-d

    Ethernet FlexNIC (NIC10) LOM:4-a

    Ethernet FlexNIC (NIC12) LOM:4-b

    Ethernet FlexNIC (NIC14) LOM:4-c

    Ethernet FlexNIC (NIC16) LOM:4-d


That doesn't match either what's in VCEM or ESXi.


Before you ask, I've gone through the configuration multiple times and it's always the same result. I've re-installed ESXi and no matter what the two blades in the second chassis always enumerate the NICs the same.


Can someone please help me to understand what should map where, what I should be seeing in VCEM and why two identical servers don't enumerate the NICs the same way.





Occasional Visitor

Re: LOM Mapping in VCEM and NIC enumeration in ESXi



Did you ever discover a solution to this issue? I have discovered the same problem on one of my blades.



Ethernet FlexNIC (NIC 1) LOM1:1-a 00:17:A4:77:04:30

Ethernet FlexNIC (NIC 5) LOM1:1-b 00:17:A4:77:04:34

Ethernet FlexNIC (NIC 9) LOM1:1-c 00:17:A4:77:04:38


Ethernet FlexNIC (NIC 2) LOM1:2-a 00:17:A4:77:04:32

Ethernet FlexNIC (NIC 6) LOM1:2-b 00:17:A4:77:04:36

Ethernet FlexNIC (NIC 10) LOM1:2-c 00:17:A4:77:04:3A