220-1201 Network Configuration Concepts — 15 Questions

Question 1

A small office has a single router with four LAN ports. The network uses the 192.168.1.0/24 subnet, and the router's LAN IP is 192.168.1.1. A technician needs to add a new printer that must have a static IP address outside the DHCP range (192.168.1.100-192.168.1.200) but still be reachable by all devices. Which IP address should the technician assign to the printer?

Accepted Answer

192.168.1.50. A static IP must be within the same subnet as the network but outside the DHCP pool to avoid conflicts. The subnet is 192.168.1.0/24, so valid addresses range from 192.168.1.1 to 192.168.1.254, with the router at .1 and DHCP pool from .100 to .200. Addresses like .50 are outside the pool and within the subnet.

Answer

192.168.1.150

Answer

10.0.0.50

Answer

192.168.2.50

Question 2

A technician is configuring a new wireless router for a home office. The customer wants to ensure that guests can access the internet but cannot see other devices on the main network. Which feature should the technician enable on the router?

Accepted Answer

Guest network. A guest network creates a separate SSID and VLAN that isolates guest traffic from the main network, allowing internet access while preventing access to local devices. This is a common feature on modern routers for security and privacy.

Answer

MAC address filtering

Answer

Port forwarding

Answer

WPS (Wi-Fi Protected Setup)

Question 3

A customer reports that their laptop connects to the office Wi-Fi but cannot access the internet. Other devices on the same network work fine. The technician checks the laptop's IP configuration and sees an IP address of 169.254.15.22. What is the most likely cause of this issue?

Accepted Answer

The laptop's DHCP client is failing to obtain an IP address.. An IP address starting with 169.254 indicates that the device was unable to obtain an IP address from a DHCP server, so it assigned itself an Automatic Private IP Addressing (APIPA) address. This typically means the DHCP server is unreachable or not responding, but since other devices work, the issue is likely with the laptop's DHCP request failing.

Answer

The DNS server is misconfigured.

Answer

The laptop's network adapter is faulty.

Answer

The DHCP server is out of available IP addresses.

Question 4

A network administrator is configuring a small business network with two subnets: 192.168.1.0/24 for employees and 192.168.2.0/24 for guests. The router has two LAN interfaces with IPs 192.168.1.1 and 192.168.2.1. A technician connects a new access point to the guest subnet switch and configures it with a static IP of 192.168.2.50. The access point can ping the router's guest interface but cannot reach the internet. The router's default route points to an ISP modem at 203.0.113.1. What is the most likely missing configuration?

Accepted Answer

NAT is not enabled for the 192.168.2.0/24 subnet on the router.. The access point can reach the router's guest interface, but not the internet. This suggests the router is not performing NAT for the guest subnet, or the router lacks a route back from the ISP modem. Typically, for internet access, the router must have NAT enabled for the guest subnet, and the ISP modem must have a route back to the guest subnet. Since the employee subnet works, the router likely has NAT for 192.168.1.0/24 but not for 192.168.2.0/24.

Answer

The access point's default gateway is set to 192.168.1.1.

Answer

The access point has a duplicate IP address.

Answer

The ISP modem is blocking traffic from the guest subnet.

Question 5

A technician is troubleshooting a connectivity issue where a user's computer can ping the default gateway but cannot access a web server at 203.0.113.50. The technician runs a tracert and sees that the first hop responds, but subsequent hops time out. What is the most likely cause?

Accepted Answer

A router along the path is misconfigured or dropping packets.. Tracert shows the path packets take to a destination. If the first hop (default gateway) responds but later hops time out, it suggests a routing issue beyond the local network, such as a misconfigured router or a firewall blocking ICMP. The fact that the gateway is reachable rules out local connectivity problems.

Answer

The default gateway is down.

Answer

The web server is offline.

Answer

The user's computer has a duplicate IP address.

Question 6

A company's network uses a /24 subnet mask. The IT manager asks a technician to configure a new server with a static IP address of 192.168.1.300. The technician knows this is invalid. What is the reason this IP address cannot be used?

Accepted Answer

The octet value 300 exceeds the maximum of 255.. IPv4 addresses are 32-bit numbers, and each octet ranges from 0 to 255. The value 300 exceeds the maximum of 255, making the address invalid. This is a fundamental concept in IP addressing.

Answer

The address is outside the private IP range.

Answer

The address is a broadcast address.

Answer

The address is a network address.

Question 7

A user complains that their desktop computer cannot connect to any network shares, but they can access the internet. The technician pings the file server by IP address successfully, but pinging by hostname fails. Which network configuration issue is most likely causing this problem?

Accepted Answer

The DNS server is not resolving local hostnames.. Successful ping by IP but failure by hostname indicates that the computer cannot resolve the server's name to an IP address. This points to a DNS issue, as DNS is responsible for translating hostnames to IP addresses. The internet access suggests the DNS server is reachable but may not have the correct records for the local server.

Answer

The DHCP server is not assigning a default gateway.

Answer

The subnet mask is incorrect.

Answer

The file server has a firewall blocking ICMP.

Question 8

A technician is troubleshooting a slow network connection for a user. The user's computer has an IP address of 192.168.1.100, subnet mask 255.255.255.0, and default gateway 192.168.1.1. The technician runs a ping to the gateway and gets replies with times around 2ms. However, pinging a server at 192.168.1.200 results in times over 500ms. The technician checks the switch and finds that the port for the user's computer is set to 10 Mbps half-duplex, while the computer's NIC is set to auto-negotiation. What is the most likely cause of the high latency?

Accepted Answer

There is a duplex mismatch between the switch port and the NIC.. A mismatch in duplex and speed settings between the switch port and the NIC can cause performance issues. When one side is set to a fixed speed/duplex and the other is set to auto-negotiation, the auto side may fail to negotiate correctly, often resulting in half-duplex operation and high error rates, leading to high latency. The switch port is manually set to 10 Mbps half-duplex, while the NIC is auto-negotiating, likely resulting in a mismatch.

Answer

The server at 192.168.1.200 is overloaded.

Answer

The user's computer has a faulty network cable.

Answer

The default gateway is misconfigured.

Question 9

A user reports that their laptop can connect to the corporate Wi-Fi but cannot access any network resources. The technician checks the IP configuration and sees an IP address of 192.168.1.105 with a subnet mask of 255.255.255.0 and a default gateway of 192.168.1.1. The technician pings the gateway successfully but cannot ping a server at 192.168.2.10. What is the most likely issue?

Accepted Answer

The default gateway does not have a route to the 192.168.2.0 subnet.. The laptop can ping its own gateway (192.168.1.1) but not a server on a different subnet (192.168.2.10). This indicates that the gateway is reachable, but routing between subnets is failing. The default gateway may not have a route to the 192.168.2.x network, or the server's gateway is not configured to route back.

Answer

The laptop's DNS server is misconfigured.

Answer

The server at 192.168.2.10 is offline.

Answer

The laptop's subnet mask is incorrect.

Question 10

A technician is setting up a new office network with 50 devices. The network must support growth up to 100 devices. The technician chooses a subnet mask of 255.255.255.0. How many usable host addresses does this subnet provide?

Accepted Answer

254. A subnet mask of 255.255.255.0 (or /24) provides 256 total addresses, with 254 usable for hosts (the first address is the network ID and the last is the broadcast address). This is sufficient for the current 50 devices and allows for growth up to 100, but not beyond 254.

Answer

255

Answer

256

Answer

128

Question 11

A technician is troubleshooting a network where users report intermittent connectivity. The technician finds that the switch logs show excessive CRC errors on multiple ports connected to different workstations. What is the most likely cause of these errors?

Accepted Answer

The Ethernet cables are run too close to power cables. This question tests understanding of network errors and their causes. CRC errors indicate data corruption during transmission, often due to physical layer issues like faulty cabling, electromagnetic interference, or damaged connectors. Since multiple ports are affected, a common cabling problem is likely.

Answer

The switch is configured with the wrong VLAN assignments

Answer

The workstations have duplicate IP addresses

Answer

The switch firmware is outdated

Question 12

A user reports that their computer cannot connect to a network share. The technician runs ipconfig and sees an IP address of 169.254.1.5. What is the most likely cause?

Accepted Answer

The DHCP server is unavailable or unreachable. This question tests understanding of Automatic Private IP Addressing (APIPA). An address in the 169.254.x.x range indicates that the device could not reach a DHCP server and assigned itself a link-local address. The cause is likely a DHCP server issue or network connectivity problem preventing DHCP discovery.

Answer

The DNS server is not resolving the share name

Answer

The network cable is unplugged or faulty

Answer

The user's account does not have permission to access the share

Question 13

A small office has a single router with four LAN ports. The network uses 192.168.1.0/24. A new printer is assigned a static IP of 192.168.1.256. What will happen when the printer is connected?

Accepted Answer

The printer will not be able to communicate on the network. This question tests knowledge of IP address ranges and valid addresses. The address 192.168.1.256 is invalid because octets in IPv4 are limited to 0-255. The printer will not communicate on the network.

Answer

The printer will work but only with devices that have a static IP

Answer

The printer will automatically obtain a valid IP via DHCP

Answer

The printer will cause an IP address conflict with the router

Question 14

A technician is setting up a new wireless network for a small office. The office has three access points (APs) that should allow seamless roaming. The technician configures all APs with the same SSID and security settings. What additional configuration is necessary to prevent clients from staying connected to a weak signal?

Accepted Answer

Adjust the minimum RSSI value on each AP. This question tests knowledge of wireless roaming and signal management. To prevent sticky clients, the technician should adjust the minimum RSSI (Received Signal Strength Indicator) settings on the APs so that clients are disconnected when the signal is weak, encouraging them to roam to a stronger AP.

Answer

Set each AP to a different channel to avoid interference

Answer

Enable WPA3 encryption on all APs

Answer

Configure the APs with different SSIDs for each AP

Question 15

During a network upgrade, a technician replaces an old 10/100 Mbps switch with a new gigabit switch. After the change, several users report that their internet connection is slow. The technician checks the switch and sees that some ports show 100 Mbps instead of 1000 Mbps. What is the most likely cause?

Accepted Answer

The connected devices have 10/100 Mbps NICs. This question tests understanding of Ethernet speed negotiation. When a device's NIC only supports 100 Mbps, the switch will auto-negotiate down to that speed. The slow speed is due to the client's hardware limitation, not the switch.

Answer

The switch ports are configured for half-duplex

Answer

The Ethernet cables are Cat5 instead of Cat5e or Cat6

Answer

The switch has a faulty power supply causing reduced performance