220-1201 Practice Test 43 — 15 Questions

Question 1

A technician is troubleshooting a VoIP phone that cannot register with the call server. The phone has a valid IP address and can ping the call server by IP. Which protocol is most likely not functioning correctly?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

SIP. The phone has a valid IP address and can ping the call server by IP, which confirms that Layer 3 connectivity and DHCP are working. However, the phone cannot register with the call server, which requires the Session Initiation Protocol (SIP) to exchange registration messages (REGISTER request and 200 OK response). If SIP is misconfigured, blocked by a firewall, or the SIP proxy is unreachable, registration will fail even though basic IP connectivity exists.

Answer

RTP

Answer

DHCP

Answer

DNS

Question 2

A technician is troubleshooting a user's laptop that cannot obtain an IP address via DHCP. The laptop shows an Automatic Private IP Addressing (APIPA) address of 169.254.x.x. Other devices on the same network obtain IPs correctly. Which protocol should the technician verify is functioning on the laptop?

Accepted Answer

DHCP. The laptop has an APIPA address (169.254.x.x), which is assigned when a DHCP client fails to receive a DHCPOFFER from any DHCP server. Since other devices on the same network obtain IPs correctly, the DHCP server and network infrastructure are functional, so the issue is isolated to the laptop's DHCP client service or its ability to send and receive DHCP messages (UDP ports 67/68). The technician must verify that the DHCP protocol is functioning correctly on the laptop, including checking that the DHCP client service is running and that no firewall is blocking DHCP traffic.

Answer

DNS

Answer

ARP

Answer

ICMP

Question 3

A network administrator notices that a critical database server is responding slowly. The server uses both TCP and UDP for different services. Which of the following is a characteristic of UDP that could explain performance issues under heavy load?

Accepted Answer

UDP does not guarantee packet delivery or order. UDP is a connectionless transport protocol that does not guarantee packet delivery, ordering, or error recovery. Under heavy load, if the database server receives UDP datagrams out of order or loses packets, the application layer must handle retransmissions and reassembly, which can degrade performance. This lack of reliability and flow control means UDP can overwhelm a server with traffic it cannot manage, leading to slow responses.

Answer

UDP retransmits lost packets automatically

Answer

UDP uses a three-way handshake to establish a connection

Answer

UDP provides flow control to prevent congestion

Question 4

A user cannot connect to a remote server using RDP. The network team confirms that the firewall allows outbound traffic on all ports. Which port is typically used for RDP and should be verified on the server side?

Accepted Answer

Port 3389. RDP (Remote Desktop Protocol) uses TCP port 3389 by default. Since the firewall allows outbound traffic on all ports, the issue is likely that the server-side firewall or the RDP service is not listening on port 3389, or the port is blocked inbound on the server's firewall. Verifying that port 3389 is open and the RDP service is running on the server is the correct next step.

Answer

Port 22

Answer

Port 23

Answer

Port 5900

Question 5

A user reports that they cannot send emails from their Outlook client, but they can receive emails. The email server is using standard ports. Which port is most likely blocked on the firewall?

Accepted Answer

25. Port 25 is the default SMTP port used for outgoing email transmission. If a firewall blocks port 25, the Outlook client cannot connect to the SMTP server to send emails, but receiving via POP3 (port 110) or IMAP (port 143) remains unaffected. This matches the user's symptom of being able to receive but not send emails.

Answer

110

Answer

143

Answer

443

Question 6

A technician is troubleshooting a legacy application that uses FTP for file transfers. The transfers work but are extremely slow. The network team mentions that the firewall is configured to inspect traffic on certain ports. Which port should be opened for FTP data transfer to improve performance?

Accepted Answer

Port 20. FTP uses two channels: a control channel on port 21 and a data channel on port 20 (in active mode). When a firewall inspects traffic, it may interfere with the dynamic negotiation of the data port, causing performance degradation. Opening port 20 allows the data channel to pass through without inspection, improving transfer speed.

Answer

Port 22

Answer

Port 23

Answer

Port 69

Question 7

A technician is configuring a network monitoring tool that uses SNMP to query network devices. Which two ports should be allowed for SNMP communication?

Accepted Answer

Port 161 and 162. SNMP uses UDP port 161 for sending queries and receiving responses between the manager and agents, and UDP port 162 for the agent to send unsolicited traps or informs to the manager. These two ports must be allowed through firewalls for proper SNMP communication.

Answer

Port 22 and 23

Answer

Port 80 and 443

Answer

Port 67 and 68

Question 8

A technician is deploying a point-to-point wireless bridge between two buildings 500 meters apart. The link must support at least 1 Gbps throughput. Both buildings have clear line of sight. Which antenna type and frequency combination is most appropriate?

Accepted Answer

Parabolic dish antennas on 5 GHz. A point-to-point bridge over 500 meters requiring 1 Gbps throughput needs high-gain, directional antennas and a frequency band with sufficient bandwidth. Parabolic dish antennas on 5 GHz provide the necessary high gain (typically 20-30 dBi) and utilize the wider 5 GHz channel bandwidth (up to 80 or 160 MHz) to achieve gigabit speeds, while maintaining a narrow beamwidth to focus the signal between the two buildings.

Answer

Omnidirectional antennas on 2.4 GHz

Answer

Yagi antennas on 2.4 GHz

Answer

Patch antennas on 5 GHz

Question 9

A technician is configuring a new file server and wants to ensure that when users type \fileserver in File Explorer, it resolves to the correct IP address. The network uses a Windows domain with Active Directory. Which network service should the technician configure to allow hostname resolution for this server?

Accepted Answer

DNS. DNS (Domain Name System) is the correct service because it resolves hostnames (like \fileserver) to IP addresses in a Windows domain environment. When a user types \fileserver in File Explorer, the client queries DNS to obtain the server's IP address, enabling SMB file sharing. Active Directory relies on DNS for service location and name resolution, making it the mandatory service for this task.

Answer

DHCP

Answer

WINS

Answer

NAT

Question 10

A technician is setting up a small network for a home office. The router's WAN port receives a public IP of 203.0.113.5 from the ISP. The technician configures the LAN with a private IP range. Which of the following is a valid private IP address for the technician to assign to a workstation?

Accepted Answer

192.168.1.10. (192.168.1.10) is correct because it falls within the private IPv4 address range defined by RFC 1918 for Class C networks (192.168.0.0/16). Private IP addresses are reserved for internal LAN use and are not routable on the public internet, making them appropriate for a workstation behind a router performing NAT.

Answer

172.32.1.10

Answer

203.0.113.10

Answer

169.254.1.10

Question 11

A user complains that they cannot access a website by its domain name, but they can access it by typing the IP address directly. The user's computer is configured to obtain DNS automatically. What is the most likely issue?

Accepted Answer

The DNS server is not responding or is misconfigured.. The user can access the website by IP address but not by domain name, which indicates that DNS resolution is failing. Since the computer is configured to obtain DNS automatically, the most likely cause is that the DNS server assigned by DHCP is not responding or is misconfigured, preventing the translation of the domain name to an IP address.

Answer

The user's computer has a static IP address that conflicts with another device.

Answer

The user's browser cache is corrupted.

Answer

The website's IP address has changed.

Question 12

A network administrator needs to connect two switches that are 200 meters apart. The connection must support 1 Gbps speed. The administrator has Cat5e cable available. However, Cat5e is only rated for 100 meters at 1 Gbps. Which device can be used to extend the distance without replacing the cable?

Accepted Answer

Network extender (repeater). A network extender (repeater) regenerates the electrical signal, allowing a Cat5e segment to exceed the 100-meter distance limitation while maintaining 1 Gbps speed. Since the administrator already has Cat5e cable and only needs to extend the reach, a repeater operates at Layer 1 to boost the signal without replacing the cable.

Answer

Media converter

Answer

PoE injector

Answer

Load balancer

Question 13

A customer reports that their new laptop can connect to websites using IP addresses but cannot resolve domain names like 'www.example.com'. Which networking tool should be used to verify the DNS server configuration on the laptop?

Accepted Answer

ipconfig /all. The ipconfig /all command displays the full TCP/IP configuration, including the DNS server addresses assigned to the laptop's network adapter. Since the user can reach websites by IP address but not by domain name, the issue is likely with DNS resolution; ipconfig /all allows verification of whether the DNS server is correctly configured or pointing to an unreachable server.

Answer

ping 8.8.8.8

Answer

nslookup www.example.com

Answer

tracert 8.8.8.8

Question 14

A customer reports that their laptop can connect to the internet via a wired connection but cannot access any network shares or printers by hostname. They can ping the IP address of the file server. Which network service is most likely misconfigured?

Accepted Answer

DNS. The user can ping the file server by IP address, which confirms that basic IP connectivity (Layer 3) is working. However, they cannot access network shares or printers by hostname, which indicates that the system cannot resolve those hostnames to IP addresses. DNS (Domain Name System) is the service responsible for translating hostnames to IP addresses, so a misconfigured DNS server or client DNS settings would cause exactly this symptom.

Answer

DHCP

Answer

NAT

Answer

ARP

Question 15

A customer reports that their Android phone's email app crashes whenever they try to open an attachment from a work email. The app worked fine last week. What is the most likely cause of this issue?

Accepted Answer

The email app's cache or data is corrupted.. The most likely cause is that the email app's cache or data has become corrupted. This corruption can prevent the app from properly processing attachments, even though it worked previously. Clearing the app's cache or data typically resolves such crashes without affecting the email server or requiring an OS update.

Answer

The email server is blocking attachments.

Answer

The phone's operating system needs to be updated.

Answer

The attachment is too large for the phone to handle.