Question 1

What is the maximum number of e1000 NICs Ethernet ports (Intel PCI-x) allowed on an ESX host?

Accepted Answer

The maximum number of e1000 NICs Ethernet ports (Intel PCI-x) on an ESX host is 32. This number reduces to 24 for e1000e NICs (PCI-e) devices.

Question 2

What is the maximum total number of virtual network switch ports per ESX host?

Accepted Answer

The maximum total number of virtual network switch ports per ESX host is 4096. This number may be reduced if other configuration maximums, such as vCenter Server or Distributed Switch limits, come into effect.

Question 3

What is the maximum number of 10Gb Intel Ethernet ports you can connect to an ESX host?

Accepted Answer

The maximum number of 10Gb Intel Ethernet ports you can connect to an ESX host is four. This allows for redundancy and sufficient bandwidth for all but the most extreme situations. Such situations are potentially unlikely candidates for virtualisation in the first place.

Question 4

What is the maximum number of PCI VMDirectPath devices per host?

Accepted Answer

The number of PCI VMDirectPatch devices per host is limited to eight. VMDirectPatch allows a guest operating system, such as Windows Server 2008, direct access to a physical PCI or PCIE device, such as a 10Gb network card, for high I/O workloads.

Question 5

Which of the following is not a load balancing method for a vSwitch?

Accepted Answer

"Route based on destination port ID" is not a valid load balancing option for a vSwitch. The correct term is "Route based on the originating port ID." This load balancing algorithm balances traffic based on where the traffic entered the vSwitch. "Route based on IP hash" balances traffic based on a hash of the source and destination IP addresses. "Route based on explicit failover" uses the highest order uplink from the active adapters, and "Route based on source MAC hash" balances traffic based on the source MAC address.

Question 6

What are the two methods used to detect network link failure in a vSwitch?

Accepted Answer

The two method used for network link failure detection in a vSwitch are link status only and beacon probing. Link status only - as the name implies - only detects fault scenarios, such as a cable being pulled or a physical switch becoming unavailable. It does not protect from configuration errors. Beacon probing actively sends and listens for probes on all links in a team.

Question 7

When configuring two virtual servers to run Microsoft Network Load Balancing in unicast mode, what option should be selected in the Notify switches option of a vSwitch?

Accepted Answer

When configuring two virtual servers to run Microsoft Network Load Balancing in unicast mode, you should ensure that No is specified in the Notify switches option of a vSwitch. This is required for correct operation of a unicast-mode NLB cluster. The same is not true for a multicast cluster.

Question 8

What is a possible reason for setting the "Promiscuous Mode" of a vSwitch to "Accept"?

Accepted Answer

One possible reason for enabling promiscuous mode on a vSwitch is to allow network sniffers to function correctly when attached to that vSwitch. By default, network frames not intended for a host connected to a vSwitch are not passed to that virtual port. Enabling promiscuous mode allows the virtual machine to receive all frames on the vSwitch.

Question 9

What are VMkernel ports used for? Choose three.

Accepted Answer

VMkernel is used for VMware vMotion, IP-based storage and Fault Tolerance. vMotion is the ability to migrate a virtual machine from one host to another with zero downtime. IP-based storage could include ISCSI, FCoE and NFS. Fault Tolerance is a feature that allows a virtual machine to be protected in the event of a host failure.

Question 10

John, a VMware administrator, has set up a VMkernel port to allow for the protection and migration of virtual machines using vMotion. However, when a junior administrator attempts to vMotion a virtual machine to another host to allow for maintenance to occur, he is unsuccessful. What is the most likely explanation for this failure?

Accepted Answer

The most likely reason for the vMotion activity to not be successful in this scenario is that John did not set the VMkernel to be used for vMotion. One physical uplink is sufficient to allow vMotion to work, though this is not best practice. vMotion is independent of any physical switch feature sets. Cat 6 cabling is not a requirement of vMotion.

Question 11

John, a junior VMware administrator, increased the number of ports on a vSwitch as it reached capacity. He is now trying to attach an additional virtual machine to the vSwitch but is unable to do so. What is a possible reason for this?

Accepted Answer

In order to increase port count on a vSwitch, you must apply the changes and then reboot the host for the changes to take effect. The number of ports can be changed using the vSphere client to access the vSwitch configuration on the host in question. Select the properties for the vSwitch, then click the ports tab and select the vSwitch item and click edit. Select the general tab and increase the port count to the required number. Finally, reboot the host.

Question 12

What command can be used to enable the Cisco Discovery Protocol directly on an ESX host?

Accepted Answer

In order to enable the Cisco Discovery Protocol directly on an ESX host you can run the esxcfg-vswitch -B command. The possible modes are listen, advertise or both. Cisco Discovery Protocol allows physical switches to advertise configuration information to be viewed elsewhere, but it can be considered a security risk because it exposes sensitive information.

Question 13

When using vNetwork Distributed Switches, what is the maximum number of distributed virtual network switch ports per vCenter instance?

Accepted Answer

The maximum number of distributed virtual network switch ports for a vCenter instance when using vNetwork Distributed Switches is 6000. vNetwork Distributed Switches allow a consistent networking configuration to be applied to hosts by centrally configuring the options in vCenter.

Question 14

What is the maximum number of hosts per vNetwork Distributed Switch?

Accepted Answer

The maximum number of hosts that can be connected to a vNetwork Distributed Switch is 64. This is a maximum limit, and fewer hosts may be possible if other maximums are breached first.

Question 15

Guy, a VMware administrator, is trying to create a vNetwork Distributed Switch but is unable to do so. He is unable to view the option to create the switch when in the ESX host's configuration section. Where should Guy create a vNetwork Distributed Switch?

Accepted Answer

vNetwork Distributed Switches are created from the Networking Inventory view in the vSphere client. They can be created from this location at any time after a vCenter server is installed, provided that the appropriate licensing has been purchased.

Question 16

What is the number of ports created when you choose the option to automatically create a default port group on a vNetwork Distributed Switch?

Accepted Answer

In the Automatically create a default port group option on a vNetwork Distributed Switch, 128 is the default number of ports. This figure can be changed to accommodate your needs, providing it stays within configuration maximums.

Question 17

What would happen if a physical adapter were moved to a vNetwork Distributed Switch from a standard virtual switch with only one uplink and virtual machines currently connected?

Accepted Answer

If you move a physical adapter to a vNetwork Distributed Switch without first moving the virtual machines to another virtual switch, then the virtual machines will lose connectivity. In order to prevent this from happening, either connect another uplink to the virtual switch first or migrate the virtual machines first.

Question 18

What is the most efficient way of migrating multiple virtual machines from a standard switch to a vNetwork Distributed Switch?

Accepted Answer

The most efficient way of migrating multiple machines to a vNetwork Distributed Switch is to use the Migrate Virtual Machine networking option in the networking inventory. This allows virtual machines to be migrated with zero downtime in bulk, thereby reducing administrative effort.

Question 19

What is the maximum number of service console ports you can create on an ESX host?

Accepted Answer

The maximum number of service console ports you can set up on an ESX host is 16. Service console ports are used for management and security.

Question 20

John, a VMware administrator, is trying to change the settings of the service console connection but is unable to do so. What is the reason for this?

Accepted Answer

If there is only one service console port, John will not be able to change its settings, as this could potentially cause a loss of connection to the service console. First add an additional service console port and establish that it is working correctly, and then you will be able to remove or change the configuration of the first service console port.

Quiz 2: ESX I Networking