VCP-DCV Practice Test 21 — 15 Questions

Question 1

An administrator configures a distributed switch with a single uplink on each host and a port group with VLAN 10. After connecting a VM to the port group, the VM cannot communicate with other VMs on the same VLAN but on different hosts. What is a likely cause?

Accepted Answer

The physical switch port is set to access mode with VLAN 10.. Option C is correct because if the physical switch port is access mode with VLAN 10, it expects untagged traffic, but vSphere will tag frames with VLAN 10, causing a mismatch. Option A is wrong because VLAN tagging is on the port group, not the VM adapter. Option B would work if trunking. Option D is irrelevant.

Answer

The distributed switch has no teaming configured.

Answer

The physical switch port connected to the uplink is set to trunk mode and is tagging the VLAN.

Answer

The VLAN ID is not set correctly on the VM's virtual network adapter.

Question 2

Which two conditions must be met for a VMkernel adapter to be used for vMotion on a distributed switch? (Choose two.)

Accepted Answer

The VMkernel adapter must be in the same subnet as the destination host.. Options B and D are correct. The VMkernel adapter must be in the same subnet as the destination host (B) and must be enabled for vMotion (D). VLAN ID can be any, static IP is not required, and uplink teaming mode is irrelevant.

Answer

The physical uplinks must be in active/standby mode.

Answer

The port group must have VLAN ID 0.

Answer

The port group must be configured with a static IP address.

Question 3

A vSphere administrator is troubleshooting connectivity issues for a virtual machine that is unable to communicate with other VMs on the same VLAN. The VM is connected to a distributed port group on a vSphere Distributed Switch (vDS). The administrator verifies that the VM's IP configuration is correct and that the port group is configured with the correct VLAN ID. However, the VM can only communicate with other VMs on the same ESXi host. What is the most likely cause?

Accepted Answer

The physical switch ports connecting the ESXi hosts are not configured as trunk ports for the VLAN.. Option C is correct because if VMs on the same VLAN cannot communicate across hosts, the physical switch ports connecting ESXi hosts are likely not configured as trunk ports for that VLAN. This prevents VLAN-tagged frames from passing between hosts. Option A is incorrect because VLAN trunking policy on the vDS is not required for basic VLAN communication; the port group VLAN ID handles tagging. Option B is incorrect because the MAC address is automatically assigned and would not cause host-only communication. Option D is incorrect because the 'forging transmits' security policy controls MAC address changes, not basic connectivity.

Answer

The vDS is not configured with a VLAN trunking policy.

Answer

The VM's network adapter is configured with the wrong MAC address.

Answer

The distributed port group has forging transmits set to reject.

Question 4

Which THREE of the following are prerequisites for configuring LACP on a vSphere Distributed Switch? (Select exactly three.)

Accepted Answer

The vSphere Distributed Switch must be configured with enhanced LACP support.. Options A, C, and D are correct. LACP requires compatible physical switches, the vDS must be in enhanced LACP mode, and the physical switch ports must be configured as LACP trunks. Option B is incorrect because the uplinks must be connected to the same physical switch to form a LAG; using different switches requires Multi-chassis LACP. Option E is incorrect because LACP does not require separate VLANs; it aggregates links regardless of VLAN config.

Answer

Each uplink must be in a separate VLAN to avoid loops.

Answer

The uplinks must be connected to different physical switches for redundancy.

Question 5

After upgrading the physical switches, the LAG (Link Aggregation Group) on a VDS does not come up. The VDS LAG configuration shows LACP active mode. The physical switch ports are configured with LACP active mode as well. What is the most likely cause?

Accepted Answer

The physical switch ports are not in a port-channel. Option A is correct because even if LACP modes match, the physical switch ports must be grouped into a port-channel or etherchannel before LACP can establish. Option B (hashing algorithm) does not prevent LACP from forming. Option C (different LAG IDs) would be incorrect if the LAG is configured identically on all hosts. Option D (system priority) might influence which side is responsible for deciding aggregation, but does not prevent the LAG from coming up if otherwise correct.

Answer

The physical switch uses a different LACP system priority

Answer

The ESXi hosts have different LAG IDs

Answer

The VDS LAG hashing algorithm is set to IP hash

Question 6

Which three factors influence the behavior of Network I/O Control (NIOC) when allocating bandwidth to different traffic types? (Choose three.)

Accepted Answer

Reservation per traffic type. Options A, B, and C are correct. NIOC uses shares, reservation, and limit to allocate bandwidth. The number of physical uplinks (D) and total physical bandwidth (E) are not configurable per traffic type, though they affect overall capacity.

Answer

The total physical bandwidth

Answer

The number of physical uplinks

Question 7

An administrator is configuring a vSphere Standard Switch. Which two settings are essential for basic network connectivity of virtual machines?

Accepted Answer

Port group name. Options A and B are correct because a port group must have a name and a VLAN ID (even if 0) to be created. Option C is incorrect because MTU can default. Option D is incorrect because the network adapter type is chosen by the VM. Option E is incorrect because the MAC address is assigned automatically.

Answer

MTU

Answer

Network adapter type (e.g., E1000)

Answer

Security policy

Question 8

A vSphere administrator needs to provide network connectivity to a set of VMs that must be isolated from all other traffic on the physical network. The VMs are on the same ESXi host and require maximum throughput between them. Which vSphere networking solution should the administrator use?

Accepted Answer

Create a standard switch with an internal-only port group (no uplinks). Option D is correct because a standard switch with no uplinks creates an internal-only network that provides isolation and maximum throughput as traffic stays within the ESXi host memory. Option A requires uplinks and VLAN configuration, allowing potential traffic exposure. Option B requires physical switch support for private VLANs and still uses uplinks. Option C incorrectly uses a VMkernel NIC, which is for management traffic, not VM data.

Answer

Create a distributed switch with a private VLAN

Answer

Create a standard switch with a VLAN-backed port group

Answer

Create a standard switch with a VMkernel NIC for inter-VM communication

Question 9

An administrator has configured a vSphere Distributed Switch (VDS) with Network I/O Control. They need to guarantee bandwidth for a specific set of virtual machines. Which method should be used?

Accepted Answer

Create a port group with a custom network resource pool.. Option C is correct because Network Resource Pools allow bandwidth reservation. Option A is incorrect because traffic shaping only limits bandwidth, not guarantees. Option B is incorrect because SR-IOV provides direct passthrough, not bandwidth control. Option D is incorrect because VLAN priority does not guarantee bandwidth.

Answer

Enable SR-IOV on the physical NICs.

Answer

Set the virtual machine's network adapter to use a specific VLAN.

Answer

Configure Traffic Shaping on the distributed switch.

Question 10

A VM cannot connect to the network after being migrated to a different host in the cluster. The VM's network adapter is connected to a standard switch port group that exists on the source host but not on the destination host. What is the most likely cause?

Accepted Answer

The standard switch is not configured on the destination host.. Option B is correct because standard switches are host-specific; the port group must exist on the destination host. Option A is not about existence. Option C is irrelevant. Option D is unrelated.

Answer

The VM's MAC address is not allowed on the destination port group.

Answer

The VLAN ID on the port group does not match.

Answer

The ESXi host's firewall is blocking the VM's traffic.

Question 11

An administrator has created a standard vSwitch port group with VLAN ID 100. Virtual machines in this port group can communicate with each other but not with devices on the physical network. What is a possible cause?

Accepted Answer

The physical switch port is not configured to pass VLAN 100.. Option B is correct because the physical switch port must be configured to pass VLAN 100, either as a trunk or access port. Option A is incorrect because duplicate MAC addresses would affect local communication too. Option C is incorrect because subnet mismatch would also affect local communication. Option D is incorrect because one uplink is sufficient.

Answer

The vSwitch has only one uplink.

Answer

The virtual machines have duplicate MAC addresses.

Answer

The virtual machines are using different subnets.

Question 12

An organization has deployed a vSphere Distributed Switch (vDS) across multiple ESXi hosts. The security team requires that no virtual machine can change its MAC address to impersonate another device. Which security policy setting on the distributed port group should be configured to fulfill this requirement?

Accepted Answer

Set 'Forged transmits' to 'Reject'.. Option B is correct because the 'Forged transmits' policy, when set to 'Reject', drops any outbound frames with a source MAC address different from the one assigned to the virtual NIC. This prevents MAC impersonation. Option A is incorrect because 'Promiscuous mode' allows the VM to see all traffic on the port, which is a security risk and unrelated to MAC impersonation. Option C is incorrect because 'MAC address changes' controls whether the VM can change its effective MAC address, but the question is about outward impersonation. Option D is incorrect because traffic shaping limits bandwidth, not MAC security.

Answer

Set 'MAC address changes' to 'Reject'.

Answer

Set 'Promiscuous mode' to 'Reject'.

Answer

Enable traffic shaping and set a low average bandwidth.

Question 13

An administrator is troubleshooting network connectivity for a virtual machine connected to a vSphere Distributed Switch. Which three components must be properly configured for the VM to communicate with the external network?

Accepted Answer

Physical NIC uplink. Options B, C, and E are correct. The physical NIC uplink provides connectivity from the host, the distributed switch uplink port group connects the DVS to the physical NIC, and the physical switch port must be configured to allow traffic. Option A is incorrect because the VM's IP address is an OS setting, not a vSphere networking component. Option D is incorrect because the VM's network adapter driver is a software component, not a configuration element.

Answer

VM's IP address

Answer

VM's network adapter driver

Question 14

An administrator needs to capture traffic from a specific virtual machine for troubleshooting. Which vSphere networking feature should be used?

Accepted Answer

Port mirroring on the VDS.. Option B is correct because port mirroring (also called SPAN) on a VDS copies traffic from a source port to a destination port for analysis. Option A is incorrect because NetFlow provides flow statistics, not packet captures. Option C is incorrect because traffic shaping controls bandwidth. Option D is incorrect because LLDP is for discovering network neighbors.

Answer

LLDP on the VDS.

Answer

NetFlow on the VDS.

Answer

Traffic shaping on the VDS.

Question 15

A network administrator notices that all traffic from two VMs connected to the same standard switch port group is going through the same physical uplink, causing congestion. The teaming policy is set to Route based on originating virtual port. What change should the administrator make to distribute traffic more evenly?

Accepted Answer

Change teaming policy to Route based on IP hash.. Option A is correct because IP hash uses source and destination IP to distribute traffic, providing better load distribution. Option B is wrong because LACP is not supported on standard vSwitches. Option C is wrong because adding uplinks without changing policy still ties port to same uplink. Option D does not distribute traffic.

Answer

Increase the number of uplinks to 4.

Answer

Enable LACP on the standard switch.

Answer

Change the load balancing policy to Explicit failover order.