Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A network technician is troubleshooting intermittent connectivity issues on a small office network. The issue only occurs for a few minutes at a time, and users lose access to both internal servers and the internet. During the issue, the technician can ping the default gateway from the core switch but not from the router. The router logs show multiple 'Duplicate IP address' errors for the router's LAN interface. Which of the following is the MOST likely cause?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
A misconfigured DHCP server on the network
While a misconfigured DHCP server could assign incorrect IP addresses, the router logs specifically indicate a duplicate IP address, which is more characteristic of a rogue device actively conflicting with the router's address.
B
Best answer
A rogue DHCP server on the network
A rogue DHCP server can hand out the router's IP address to another device, causing an IP conflict that makes the router unreachable intermittently. This matches the symptoms of intermittent connectivity and duplicate IP errors.
C
Distractor review
A spanning tree protocol convergence loop
Spanning tree loops cause network floods, high switch CPU usage, and broadcast storms, but they do not generate duplicate IP address errors. The symptoms described do not match STP issues.
D
Distractor review
A faulty network cable causing CRC errors
CRC errors cause packet corruption and retransmissions, leading to slow or intermittent connectivity, but they do not result in duplicate IP address errors in router logs. The symptoms point to an IP conflict, not physical layer issues.
Common exam trap
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Technical deep dive
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
- CIDR notation defines the prefix length.
- Block size helps identify subnet boundaries.
- Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
- The required host count determines the smallest suitable subnet.
TExam Day Tips
- Write the block size before choosing the subnet.
- Check whether the question asks for hosts, subnets or a specific address range.
- Do not confuse /24, /25, /26 and /27 host counts.
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More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A user reports intermittent network connectivity on a desktop computer. The technician observes that the Ethernet link light on the NIC turns off for a few seconds and then turns back on. The cable passes a wiremap test, the switch port is verified good with another device, and the NIC driver is updated. The issue occurs more frequently when the computer's case fan runs at high speed. Which of the following is the MOST likely cause?
Question 2
A workstation is unable to connect to the internet. The technician runs the 'ipconfig' command and sees the IPv4 address is 169.254.15.200 with a subnet mask of 255.255.0.0. The workstation can ping other devices on the local subnet but cannot ping the default gateway or any external addresses. Which TWO actions should the technician take to resolve this issue? (Select two.)
Question 3
A workstation is connected to a managed switch. It obtains a valid IP address (192.168.10.50) from the DHCP server, but it cannot ping the default gateway (192.168.10.1). The link light on both the workstation NIC and the switch port are solid green. Other workstations on the same switch CAN ping the default gateway successfully. The technician accesses the switch management interface and finds that the workstation's port is configured as an access port on VLAN 10. The default gateway is located on VLAN 20. An inter-VLAN router is configured but not explicitly allowing VLAN 10 access to VLAN 20. Which of the following is the MOST likely cause of the problem?
Question 4
A company develops a web application that relies on a custom library available only for a specific Linux distribution. They want to deploy the application in the cloud with minimal administrative overhead, but they need full control over the software stack, including the ability to install the custom library and configure the web server. Which cloud service model BEST meets these requirements?
Question 5
A company has a legacy virtual machine running on a deprecated hypervisor (Hyper-V). They want to migrate this VM to a new hypervisor (VMware vSphere) hosted in a private cloud while preserving the VM's configuration, installed applications, and data. The migration must be performed with minimal downtime. Which of the following methods is MOST appropriate?
Question 6
A company hosts a critical database on a virtual machine in a public cloud. The database requires persistent storage that must be retained even if the VM is terminated. The storage must also be accessible from multiple VMs simultaneously for a future high-availability configuration. Which type of cloud storage BEST meets these requirements?
FAQ
Questions learners often ask
What does this 220-1101 question test?
CIDR notation defines the prefix length.
What is the correct answer to this question?
The correct answer is: A rogue DHCP server on the network — Duplicate IP address errors indicate that another device on the network is using the same IP as the router's LAN interface. This conflict causes the router to become unreachable from clients when the rogue device responds to ARP requests. A rogue DHCP server is a common source of such conflicts, as it hands out IP addresses that may overlap with statically assigned addresses. A misconfigured DHCP server could cause similar issues but the duplicate IP specifically points to a conflict. Spanning tree loops cause broadcast storms and high CPU, not duplicate IP errors. Faulty cables cause CRC errors but not IP conflicts.
What should I do if I get this 220-1101 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
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