VCP-DCV Practice Test 23 — 15 Questions

Question 1

A vSphere administrator is configuring Network I/O Control (NIOC) on a vSphere Distributed Switch to prioritize vMotion traffic during maintenance windows. The environment has three system traffic classes: Management, NFS, and vMotion. The administrator wants to ensure that when the network is congested, vMotion gets at least 50% of the available bandwidth, while Management and NFS each get at least 25%. Which NIOC configuration achieves this?

Accepted Answer

Set the vMotion traffic class shares to 50, Management shares to 25, and NFS shares to 25.. Option A is correct because shares allocate bandwidth proportionally during contention. Setting shares to 50/25/25 gives vMotion 50% of the bandwidth when all are busy. Option B is incorrect because reservations guarantee minimum bandwidth but do not guarantee proportional allocation; plus, the question asks for 'at least' percentages during congestion, which shares handle. Option C is incorrect because limits cap bandwidth and would prevent vMotion from using more than 500 Mbps, not guaranteeing 50% of available bandwidth. Option D is incorrect because disabling NIOC removes prioritization, making all traffic equal.

Answer

Set a limit of 500 Mbps for Management and NFS, and no limit for vMotion.

Answer

Set a reservation of 500 Mbps for vMotion, 250 Mbps for Management, and 250 Mbps for NFS.

Answer

Do nothing; NIOC is not needed because all traffic types are equally important.

Question 2

An administrator needs to configure a vSphere Standard Switch (vSS) for a small environment. Which component must be created first before adding a virtual machine to the network?

Accepted Answer

Create a standard switch.. Option A is correct because a standard switch must exist to create port groups. Without the switch, port groups cannot be created. Option B is incorrect because the uplink is part of the switch creation. Option C is incorrect because a VM port group is created after the switch. Option D is incorrect because the VMkernel interface is for management/storage, not for regular VM connectivity.

Answer

Configure a VMkernel interface.

Answer

Create a virtual machine port group.

Answer

Add a physical uplink to the host.

Question 3

A vSphere environment uses a vSphere Distributed Switch (vDS) with 10G uplinks and Network I/O Control (NIOC) enabled. Administrators report that during peak traffic, NFS storage traffic is experiencing high latency, while other traffic types remain unaffected. The vDS has default NIOC shares and limits. Which action should be taken to prioritize NFS traffic without completely starving other traffic?

Accepted Answer

Increase the shares for the NFS traffic class.. Option D is correct because increasing the shares for the NFS system traffic class gives it a higher proportion of bandwidth during contention, without imposing a hard limit. Option A is incorrect because setting a high limit for NFS could starve other traffic if NFS uses all bandwidth. Option B is incorrect because setting a low limit for NFS would cap NFS traffic, worsening performance. Option C is incorrect because disabling NIOC removes all prioritization, making all traffic equal and not solving the issue.

Answer

Set a low bandwidth limit for the NFS traffic class.

Answer

Set a high bandwidth reservation for the NFS traffic class.

Answer

Disable Network I/O Control on the vDS.

Question 4

An administrator is troubleshooting an issue where a VM on a vSphere Distributed Switch cannot receive traffic from outside its subnet. The VM can send traffic out and receive replies from hosts on the same subnet. The default gateway is configured correctly. What is the most likely cause?

Accepted Answer

The router does not have a route back to the VM's subnet.. Option B is correct because if the route is missing on the physical router back to the VM's subnet, the router drops return traffic. This is a common routing misconfiguration. Option A is incorrect because the default gateway is the VM's gateway; the ESXi host's management gateway is unrelated. Option C is incorrect because the VTEP IP is for VXLAN, not regular routing. Option D is incorrect because a port group VLAN mismatch would cause issues with same-subnet communication as well.

Answer

The VXLAN Tunnel Endpoint (VTEP) IP is not reachable from the remote subnet.

Answer

The ESXi host's default gateway is misconfigured.

Answer

The port group VLAN ID is different from the physical switch trunk allowed VLAN.

Question 5

A vSphere administrator notices that VMs on a specific ESXi host lose connectivity intermittently. The VMs are on a distributed switch port group. The administrator finds that the Uplink 1 on that host is down. What should the administrator do first?

Accepted Answer

Check the physical switch port configuration for the failed uplink. Option C is correct because the first step is to verify the physical switch port configuration for the failed uplink, as it may be misconfigured, disabled, or have a faulty cable. Option A would be premature without knowing the root cause. Option B might help if failover is needed but does not address the root cause. Option D adjusts load balancing but does not fix the down uplink.

Answer

Increase the number of uplinks in the teaming policy

Answer

Set the load balancing policy to Route based on source MAC

Answer

Configure a different failover order

Question 6

A virtual machine is configured with two vNICs connected to different standard port groups (VLAN 10 and VLAN 20). The administrator wants to use both vNICs for load balancing and failover within the VM OS. Which condition must be met on the vSwitch side?

Accepted Answer

Configure NIC teaming within the guest operating system.. Option C is correct because the VM OS must have NIC teaming configured to use both interfaces. The vSwitch port groups are separate, so they don't team at the virtual switch level. Option A is incorrect because teaming at vSwitch is per port group, not across port groups. Option B is incorrect because MAC address changes are not needed. Option D is incorrect because route based on IP hash is for a single port group.

Answer

Enable MAC address changes on both port groups.

Answer

Configure teaming on the standard switch by bridging the two port groups.

Answer

Set load balancing to 'Route based on IP hash' on both port groups.

Question 7

Which two actions must the administrator take to ensure network connectivity for VMs on a new distributed switch?

Accepted Answer

Add the ESXi hosts to the distributed switch. The correct answers are A and B. Adding the ESXi hosts to the distributed switch (A) is necessary for them to use the switch. Creating a port group and assigning a VLAN ID (B) provides the network layer connectivity. Option C (setting MTU to 9000) is optional and not required for basic connectivity. Option D (configuring a VMkernel interface) is for host management, not VM connectivity. Option E (enabling NIOC) is optional for QoS.

Answer

Configure a VMkernel interface on the distributed switch

Answer

Set the MTU to 9000

Answer

Enable Network I/O Control

Question 8

A vSphere administrator notices that after adding a new ESXi host to a vSphere Distributed Switch (vDS), some VMs on existing hosts lose network connectivity intermittently. What is the most likely cause?

Accepted Answer

The vDS MTU setting does not match the physical network MTU.. Option D is correct because if the Maximum Transmission Unit (MTU) is inconsistent across the vDS and physical network, it can cause packet drops and intermittent connectivity. Option A is incorrect because a physical uplink failure affecting all VMs is unlikely to occur only after adding a new host. Option B is incorrect because LACP issues would cause complete failure or reduced throughput, not intermittent connectivity on existing hosts. Option C is incorrect because Network I/O Control is about bandwidth allocation, not connectivity loss.

Answer

The new host's physical uplink is faulty, causing broadcast storms.

Answer

The vDS is configured with LACP, and the new host's links are not properly bundled.

Answer

The vDS Network I/O Control settings are not evenly distributed.

Question 9

Which three types of traffic can be assigned to a separate VMkernel adapter on an ESXi host?

Accepted Answer

Management traffic. The correct answers are A, C, and D. vMotion (A), management (C), and vSAN (D) are all types of traffic that use VMkernel adapters and can be assigned to separate adapters for performance or security. Fault Tolerance logging (B) also uses VMkernel but is not as commonly separated; however, the question asks for exactly three, and B is a distractor. Virtual machine network traffic (E) uses port groups, not VMkernel adapters.

Answer

Virtual machine network traffic

Answer

Fault Tolerance logging

Question 10

Which TWO of the following are valid considerations when configuring a vSphere Distributed Switch with 10G uplinks and planning for a TCP/IP stack for vMotion? (Select exactly two.)

Accepted Answer

Enable vMotion to use a separate TCP/IP stack to avoid competing with management traffic.. Options A and D are correct. A dedicated TCP/IP stack for vMotion isolates vMotion traffic and avoids contention. Using a separate VMkernel interface with a dedicated stack is standard. Option B is incorrect because the storage TCP/IP stack is for NFS/iSCSI, not vMotion. Option C is incorrect because the default TCP/IP stack is a single stack; you need a dedicated stack for isolation. Option E is incorrect because jumbo frames are an MTU setting on the vDS, not a TCP/IP stack component.

Answer

Configure the default TCP/IP stack to handle vMotion traffic with multiple gateways.

Answer

Enable jumbo frames on the vMotion TCP/IP stack to improve performance.

Answer

Use the provisioned TCP/IP stack for vMotion to leverage storage traffic isolation.

Question 11

A company has a single ESXi host with a standard switch. The administrator creates a new port group for a DMZ network and assigns a VM to it. The VM cannot ping the default gateway. The physical switch port is configured as a trunk with VLAN 100 allowed. The port group VLAN ID is set to 100. The physical NIC is connected to the switch port and shows link up. What should the administrator do to resolve the issue?

Accepted Answer

Verify the VM's IP configuration. Option C is correct because the physical and virtual networking configurations appear correct (VLAN 100 on both sides, link up), so the issue is likely an IP misconfiguration on the VM itself. Option A (change VLAN to 0) would break connectivity. Option B (enable VLAN tagging) is unnecessary as the port group already tags VLAN 100. Option D (add second NIC) does not address the connectivity problem.

Answer

Enable VLAN tagging on the physical switch port

Answer

Change the VLAN ID to 0

Answer

Add a second physical NIC to the standard switch

Question 12

Which TWO of the following are functions of a vSphere Distributed Switch that are not available in a vSphere Standard Switch? (Select exactly two.)

Accepted Answer

Port mirroring (Distributed Port Mirroring).. Options B and C are correct. Network I/O Control (NIOC) is only available on vDS. Port mirroring (using Distributed Port Mirroring) is a vDS-only feature. Option A is incorrect because VLAN tagging is available on both switch types. Option D is incorrect because NIC teaming is available on standard switches as well. Option E is incorrect because traffic shaping is available on standard switches (per port group).

Answer

NIC teaming with explicit failover order.

Answer

Traffic shaping policies.

Answer

VLAN tagging and trunking.

Question 13

An organization uses a VDS with 4 hosts. They want to use Network I/O Control (NIOC) to prioritize vMotion traffic over management traffic. After configuring NIOC, the administrator notices that vMotion performance is not improved. What could be the cause?

Accepted Answer

The vMotion VMkernel adapter is not assigned to the correct network resource pool. Option B is correct because NIOC requires that each traffic type be assigned to a network resource pool; if the vMotion VMkernel adapter is not assigned to the vMotion resource pool, NIOC does not apply. Option A (NIOC not enabled) would prevent any NIOC functionality, but the administrator configured NIOC, so it is likely enabled. Option C (oversubscribed uplinks) could affect performance but does not explain why NIOC prioritization is ineffective. Option D (CoS marking) is unrelated to NIOC shares.

Answer

The physical uplinks are oversubscribed

Answer

The vMotion traffic is not marked with the appropriate CoS tag

Answer

NIOC is not enabled on the VDS

Question 14

Based on the Healthcheck output for a distributed port (DVS Port 1) on dvs0, what can be concluded?

Accepted Answer

The physical switch is correctly configured for VLAN 100 and MTU 1500 on the uplinks connected to this host.. Option A is correct because the Healthcheck shows VLAN ID 100 and MTU 1500 with 'OK' status, indicating the physical network is properly configured for those values. Option B is incorrect because the Healthcheck does not evaluate speed/duplex. Option C is incorrect because the teaming policy is shown as 'Route based on originating virtual port', which is a valid policy. Option D is incorrect because the Healthcheck does not measure performance; it only checks configuration consistency.

Answer

The uplinks vmnic0 and vmnic1 are operating at 10 Gbps.

Answer

The load balancing policy is set to 'Route based on IP hash'.

Answer

The port is experiencing high packet loss due to misconfiguration.

Question 15

Which THREE memory-related metrics in esxtop indicate that a virtual machine is experiencing memory pressure? (Choose three.)

Accepted Answer

SWCUR. ACTV shows active memory; SWCUR indicates current swapped memory; MCTLSZ shows memory balloon driver size. These directly indicate pressure. %SYS is CPU-related, %RDY is CPU ready.

Answer

%SYS

Answer

ACTV

Answer

%RDY