Section 8 – Perform Basic Troubleshooting and Alarm Management
- Objective 8.3 – Perform Basic Troubleshooting for Networking
QUESTION 31
When an explicit failover order has not been configured on a virtual switch with multiple uplinks, what determines which uplink is used when a failover event occurs?
A.The uplink with the shortest route
B.The next available uplink on the list
C.The reported uptime for the surviving uplinks
D.The first available uplink that reports a positive Link State
Answer: C
Explanation:
Networking Virtual Machines Jon Hall Technical Trainer, VMWORLD 2006, slide 27.
Failover is implemented by the VMkernel based upon configurable parameters
1. Failover order: Explicit list of preferred links (uses highest-priority link which is up)
2. 1. Maintains load balancing configuration
2. Good if using a lower bandwidth standby NIC
3. Rolling failover — preferred uplink list sorted by uptime [C above]
The uplink with the shortest route – all uplinks are on the same network and so have the same route [A is incorrect]
The next available uplink on the list has not been defined if explicit failover order is not selected [B is incorrect]
QUESTION 32
Which of the following resource management techniques could be used to relieve a network bottleneck caused by a VM with occasional high outbound network activity?
A.apply traffic shaping to the port group containing the virtual machine
B.apply traffic shaping to the other VMs in the same port group
C.apply traffic shaping to the VM with high activity
D.convert the switch from a vNetwork Standard Switch to a vNetwork Distributed Switch
Answer: A
Explanation:
Edit the Traffic Shaping Policy for a Virtual Switch – Vcenter Help
ESX/ESXi allows you to shape outbound traffic on virtual switches. The traffic shaper restricts the network bandwidth available to any port, but may also be configured to temporarily allow “bursts” of traffic to flow through a port at higher speeds.
Procedure
1 Log in to the vSphere Client and select the server from the inventory panel.
2 Click the Configuration tab and click Networking.
3 Select a vSwitch and click Properties.
4 Click the Ports tab.
5 Select the vSwitch and click Edit.
6 Click the Traffic Shaping tab.
7 Select Enabled from the Status drop-down menu to enable traffic shaping policy exceptions.
The Status policy here is applied to each virtual adapter attached to the port group, not to the vSwitch as a whole. If you enable the policy exception in the Status field, you set limits on the amount of networking bandwidth allocation for each virtual adapter associated with this particular port group. If you disable the policy, services have a clear connection to the physical network by default.
8 For each traffic shaping policy, enter a bandwidth value.
QUESTION 33
The remote console performance for a virtual machine on an ESXi Host appears to be degraded. Which of the following could be a possible cause of the problem (Choose Two)?
A.The physical NIC assigned to the VMkernel port group has a speed or duplex mismatch
B.The virtual NIC assigned to the virtual machine has a speed or duplex mismatch
C.The physical NIC assigned to the virtual machine port group containing the affected virtual machine has a speed or duplex mismatch
D.The physical NIC assigned to the Service Console port group has a speed or duplex mismatch
Answer: AC
QUESTION 34
An administrator needs to determine the current network adapter configuration for an uplink on an ESX Host. Which of the following items can be viewed from the Network Adapters section of the Configuration tab using the vSphere Client (Choose Three)?
A.Jumbo Frame support
B.Wake on LAN support
C.Observed IP ranges
D.Speed and Duplex settings
E.TCP Segmentation Offload (TSO) support
Answer: BCD
Explanation:
The screenshot below shows Speed and Duplex settings, Observed IP ranges and Wake on LAN support items.
QUESTION 35
Beacon Probing is used in vSphere networking to?
A.identify which uplink has the longest reported uptime
B.discover alternate default gateway addresses
C.identify when an upstream link failure has occurred
D.discover which uplink has the shortest route
Answer: C
Explanation:
VMware Knowledgebase KB 1005577
What is beacon probing? When is it recommended to be used?
Beacon Probing is a network failover detection mechanism that sends out and listens for beacon probes on all NICs in the team and uses this information, in addition to link status, to determine link failure.
QUESTION 36
VMware Converter Enterprise requires the following TCP ports to be open:
A.139, 902, 905
B.139, 443, 902
C.139, 443, 445
D.443, 902, 905
Answer: C
Explanation:
Required Ports
Converter Enterprise for VirtualCenter (plugin)
* Converter Enterprise Server to remote physical machine – TCP 445, 139 and UDP 137,
* Converter Enterprise Server to VirtualCenter Server – 443
* Converter Enterprise Client to Converter Enterprise Server – 443
* Physical machine to VirtualCenter Server – 443
* Physical machine to ESX Server – 443, 902
QUESTION 37
Exhibit:
Which statement is true about the network performance of the virtual machine (VM) shown in the exhibit?
A.Virtual Switch auto-negotiation settings need to be adjusted to improve performance.
B.The VM can send traffic as fast as the underlying physical NIC.
C.The underlying physical NIC is configured for 100 Mbps/half-duplex.
D.The VM can send at the maximum of 10 Mbps.
Answer: B
QUESTION 38
What are the two possible storage multipathing policies that you can set on an ESX Server 3.0? (Choose two.)
A.Most Recently Used (MRU)
B.Open Shortest Path First (OSPF)
C.Persistent Binding
D.Fixed
E.Dynamic Load Balancing
Answer: AD
Explanation:
Fibre Channel SAN Configuration Guide ESX Server 3.5, ESX Server 3i version 3.5
VirtualCenter 2.5, page 42.
You can choose a multipathing policy for your system, either Fixed or Most Recently Used
QUESTION 39
You want to troubleshoot poor remote console performance. Which is a possible cause of the problem?
A.The physical NIC assigned to the virtual machine port group has a speed or duplex mismatch.
B.The virtual machine has an IP address conflict.
C.To conserve memory, the ESX Server has initiated Transparent Page Sharing.
D.The virtual NIC assigned to the virtual machine has a speed or duplex mismatch.
Answer: A
QUESTION 40
You are experiencing traffic overload on an Uplink network adapter. Which three actions can be taken to reduce the overload? (Choose three.)
A.move virtual machines to other vSwitches to reduce contention
B.add NIC teaming to increase the available bandwidth
C.add the VMkernel TCP/IP networking stack to improve performance
D.move virtual machines to other VLAN port groups on the same vSwitch
E.configure traffic shaping to reduce contention
Answer: ABE
