220-1101 TCP & UDP Ports Practice Test 2 — 15 Questions

Question 1

A technician is setting up a network printer that supports both LPD (Line Printer Daemon) and IPP (Internet Printing Protocol). The printer must be accessible from Windows and Linux clients. Which port should be opened for IPP?

Accepted Answer

631. IPP uses TCP port 631. LPD uses port 515. Port 9100 is used by some HP printers for direct printing (JetDirect). Port 80 is HTTP, which is not typically used for printing.

Answer

515

Answer

9100

Answer

80

Question 2

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 connectionless and does not guarantee delivery, so it does not retransmit lost packets. Under heavy load, packet loss can increase without recovery, causing application-level issues. TCP retransmits lost packets, which can add latency but ensures delivery.

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 3

A user reports that they cannot access a website hosted on a remote server. The technician finds that the firewall allows HTTP and HTTPS traffic, but the website uses a non-standard port. The user's browser shows 'connection refused'. Which tool can the technician use to verify if the remote port is open?

Accepted Answer

Telnet. Telnet can be used to test connectivity to a specific port (e.g., telnet example.com 8080). Ping uses ICMP, not TCP ports. Nslookup tests DNS resolution. Tracert traces the route but does not test port status.

Answer

Ping

Answer

Nslookup

Answer

Tracert

Question 4

A user wants to securely transfer files to a remote server using a command-line tool. Which port is the default for SFTP (SSH File Transfer Protocol)?

Accepted Answer

22. SFTP runs over SSH, which uses port 22 by default. Port 21 is for standard FTP, port 20 is FTP data, and port 990 is FTPS (FTP over SSL).

Answer

21

Answer

20

Answer

990

Question 5

A security audit reveals that an internal file server is listening on multiple ports, including 137, 138, 139, and 445. The auditor recommends disabling older protocols. Which port is associated with SMB over TCP/IP directly (without NetBIOS)?

Accepted Answer

445. Port 445 is used by SMB directly over TCP/IP (also known as SMB over TCP). Ports 137-139 are used by NetBIOS over TCP/IP, which is older and less secure. Port 443 is HTTPS, and port 21 is FTP.

Answer

137

Answer

139

Answer

443

Question 6

A user wants to access their company's webmail using a secure connection from a public Wi-Fi hotspot. The webmail server is configured to use IMAP over SSL. Which port should the email client use?

Accepted Answer

993. IMAP over SSL (IMAPS) uses port 993. This provides encrypted access to email, protecting credentials and data on public networks.

Answer

143

Answer

110

Answer

995

Question 7

A small office uses a network printer that supports both IPP and LPD printing. The printer is configured to use the default port for IPP. Which port must be open on the firewall for printing to work?

Accepted Answer

631. Internet Printing Protocol (IPP) uses port 631 by default. Opening this port allows print jobs to be sent to the printer over the network.

Answer

515

Answer

9100

Answer

80

Question 8

During a security audit, a technician discovers that an internal web server is responding on port 8080 instead of the standard HTTP port. What is the most likely reason for this configuration?

Accepted Answer

The server is configured as a web proxy or alternate HTTP server.. Port 8080 is commonly used as an alternative HTTP port, often for proxy servers or to avoid conflicts with standard port 80. It allows HTTP traffic without using the default port.

Answer

The server is running HTTPS on a non-standard port.

Answer

The server is running an FTP service.

Answer

The server is using a custom application protocol.

Question 9

A network administrator needs to allow secure remote administration of a router using SSH. The router is configured to use the default SSH port. Which port must be opened on the firewall?

Accepted Answer

22. SSH (Secure Shell) uses port 22 by default for secure remote administration. Opening this port allows encrypted command-line access to the router.

Answer

23

Answer

161

Answer

443

Question 10

A user needs to transfer files securely between two Linux servers over the internet. Which port should be allowed through the firewall for this purpose?

Accepted Answer

22. SFTP (SSH File Transfer Protocol) uses port 22, the same as SSH, for secure file transfers. It provides encryption and authentication.

Answer

21

Answer

20

Answer

443

Question 11

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. SMTP uses port 25 for sending email, while POP3 (port 110) or IMAP (port 143) are used for receiving. Blocking port 25 prevents outgoing email but not incoming.

Answer

110

Answer

143

Answer

443

Question 12

A customer complains that their web browser cannot load any HTTPS websites, but HTTP sites work fine. The firewall is configured to allow common ports. Which port is most likely being blocked?

Accepted Answer

443. HTTPS uses port 443 for secure web traffic. If port 443 is blocked, HTTPS sites won't load, but HTTP (port 80) will still work.

Answer

80

Answer

22

Answer

53

Question 13

A technician is configuring a new database server that needs to accept remote connections from client applications using the default port for MySQL. Which port should be opened in the firewall?

Accepted Answer

3306. MySQL uses port 3306 by default for client connections. Opening this port allows remote database access.

Answer

1433

Answer

1521

Answer

5432

Question 14

A technician is troubleshooting a DHCP issue where clients are not receiving IP addresses. Which port must be open on the firewall for DHCP server communication?

Accepted Answer

67. DHCP uses UDP ports 67 (server) and 68 (client). Opening port 67 allows DHCP server broadcasts to reach clients.

Answer

68

Answer

53

Answer

123

Question 15

During a network upgrade, a technician needs to allow remote desktop connections to Windows workstations from the internal network. Which port must be opened in the firewall?

Accepted Answer

3389. Remote Desktop Protocol (RDP) uses port 3389 by default. Opening this port allows remote desktop connections to Windows machines.

Answer

22

Answer

23

Answer

5900