Which two statements are true about this configuration? (Choose two

A vSphere 5.x implementation contains two ESXi hosts, ESXi01and ESXi02. There is a virtual machine “VM21” connected to the Production port group on ESXi01.

ESXi01 has the following switch configuration.

vSwitch0, single uplink to 10.1.20.0/24

Production port group

VMkernel port for vMotion

VMKernel port for management

vSwitch1, single uplink to 10.1.40.0/24

Engineering port group

VMKernel port for NFS storage

ESXi02 has the following switch configuration.
vSwitch0, single uplink to 10.1.20.0/24

Engineering port group

VMkernel port for vMotion

VMKernel port for management

vSwitch1, single uplink to 10.1.40.0/24

Production port group

VMKernel port for NFS storage

Which two statements are true about this configuration? (Choose two.)

A.
vMotion is not available between the two hosts

B.
If VM21 is migrated to ESXi02 it will not be available on the network

C.
The virtual machine can be vMotion migrated to the target host.

D.
Broadcasts from the Production port group will not reach the Engineering port group.

16 Comments on “Which two statements are true about this configuration? (Choose two

  1. Kid A says:

    I really don’t get this question. In reading it, the networks look the same(?) If so, why is B correct? And no idea why VMware keeps asking network broadcast questions, either.

  2. Ricky says:

    No it is not the same. On ESX01, Production port group is on VS0 which is connected to 10.1.20.0/24 network. Let’s say on the physical side, it is in one VLAN. Engineering port group is on VS1 and connected to 10.1.40.0/24 network. If VM21 from Production group (10.140.20.0/24 network) is migrated to ESX02, it will end up connected to VS1 Production group port, which is connected to 10.1.40.0/24 network (different VLAN). So answer B is right. I’m not sure about answer D.

  3. angryant says:

    Re: D (broadcasts)
    check pg 20 (I don’t think in ver. 5 it’s different)
    http://www.vmware.com/pdf/vsphere4/r40/vsp_40_esx_server_config.pdf

    Each port group is identified by a network label, which is unique to the current host. Network labels are used
    to make virtual machine configuration portable across hosts. All port groups in a datacenter that are physically
    connected to the same network (in the sense that each can receive broadcasts from the others) are given the
    same label. Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels.

  4. Bob says:

    Boradcasts from the production portgroup on esxi01 (.20/24) will most certainly reach the engineering portgroup on esxi02 (.20/24). How is D correct?

  5. Mtol20 says:

    A: false
    vmotion is aivalable on vswitch0 on both esxi hosts in network 10.1.20 so vmotion should work
    B: true
    Vm21 is connected to prod port group witch is 10.1.20 on Esxi01 but on Esxi02 prod port group is 10.1.40 so vm will not be reachable on the network
    C: true
    vmotion is aivalable on vswitch0 on both esxi hosts in network 10.1.20 so vmotion / migration should work
    D: false
    Broadcast from production on Esxi01 witch is 10.1.20 will reach Engineering on Esxi02 witch also has 10.1.20 as uplink so when both Esxi hosts have vm’s running, vm’s on Esxi01 in prod can reach vm’s on Esxi02 from engineering and vice versa.

  6. commtech says:

    vSphere vMotion Networking Requirements
    (ESXi and vCenter Server 5.1 Documentation)

    Ensure that virtual machines have access to the same subnets on source and destination hosts.

  7. jackal99a says:

    B and C are correct.

    D.
    Broadcasts from the Production port group will not reach the Engineering port group.

    YES they will – Port Groups are not associated with IPs, rather VLANS – in this case with the combination of both HOSTs – the Port Groups straddle both VLANS – A VLAN is by definition just a broadcast domain… So regardless of IP the packets will span both.

    Also B basically states the VM will vmotion over and become available, because vmotion is just looking for PortGroup name matches.

  8. nadeemka2000 says:

    Each port group is identified by a network label, which is unique to the current host. Network labels are used to make virtual machine configuration portable across hosts. All port groups in a datacenter that are physically connected to the same network (in the sense that each can receive broadcasts from the others) are given the same label. Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels.

  9. David says:

    I took a while to get it, because I’m new to VMware, but B and D are right..
    A INCORRECT: vMotion is available (if the VM is not connected to the port group)
    B CORRECT: you can COLD migrate the VM, but the port group label is different so it won’t have connectivity in the other host
    C INCORRECT: you can COLD migrate it, but NOT VMOTION it, because the port group labels are not consistent.
    D CORRECT: same as C, the label are distinct so broadcast cannot be received (see other comments for explanation).
    Sure is that this is a tricky-not-a-1-minute question for the exam..damn vmware!
    Thanks you all for the comments!

  10. Luay says:

    D is wrong since the two port groups share the same physical switch VLAN (because they are on the same network) broadcast from Prod PG on Esxi01 will reach machines from Eng PG on Esx02 and vise versa .

    C is correct because although the VLAN are not the same but the vmotion checks if a PG with the same lable exists on the destination host and in this case both Prod and Eng PGs are available on both host .

  11. Ricky says:

    Luay,

    Unfortunately the question doesn’t state that they are using a standard or a distributed switch. But assuming they are on a standard switch, then there’s 2 things from the documentation to understand for vMotion.

    “If you are using standard switches for networking, ensure that the network labels used for virtual machine port groups are consistent across hosts. During a migration with vMotion, vCenter Server assigns virtual machines to port groups based on matching network labels.”

    “Ensure that virtual machines have access to the same subnets on source and destination hosts”

    Based on the 2 statements above, if you were to vMotion VM21 somehow, vCenter will automatically choose the same label “Production” port group on ESXi02 which is not on the same subnet as ESXi01’s “Production” port group. Therefore, vMotion will fail. So C is incorrect.

    And to confirm, plus this one is a lot easier to understand.
    “Conversely, if two port groups cannot receive broadcasts from each other, they have distinct labels”

    So Answer is B and D


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