CS MCQs

Protocols and Ports MCQs, Set 1 of 1

Q1 / 14

  1. Q1. Which port does HTTP use by default?

    • A.21
    • B.25
    • C.80(correct answer)
    • D.443

    HTTP uses port 80; HTTPS uses 443.

  2. Q2. Which port does HTTPS use by default?

    • A.80
    • B.443(correct answer)
    • C.8080
    • D.22

    HTTPS is HTTP over TLS on port 443.

  3. Q3. SSH uses which default port?

    • A.21
    • B.22(correct answer)
    • C.23
    • D.25

    SSH listens on port 22.

  4. Q4. Which protocol translates domain names into IP addresses?

    • A.DHCP
    • B.DNS(correct answer)
    • C.FTP
    • D.SNMP

    DNS is the internet’s phone book.

  5. Q5. DNS queries normally use which port?

    • A.53(correct answer)
    • B.67
    • C.110
    • D.143

    DNS uses port 53, mostly over UDP.

  6. Q6. Which protocol automatically gives IP addresses to devices on a network?

    • A.DNS
    • B.ARP
    • C.DHCP(correct answer)
    • D.NAT

    DHCP leases addresses and settings such as the gateway and DNS server.

  7. Q7. Which protocol sends email between mail servers?

    • A.POP3
    • B.IMAP
    • C.SMTP(correct answer)
    • D.HTTP

    SMTP sends mail; POP3 and IMAP are used to read it.

  8. Q8. Which protocol lets a mail client keep messages on the server and sync folders?

    • A.POP3
    • B.IMAP(correct answer)
    • C.SMTP
    • D.FTP

    IMAP keeps mail on the server; POP3 usually downloads and removes it.

  9. Q9. The ping command uses which protocol?

    • A.TCP
    • B.UDP
    • C.ICMP(correct answer)
    • D.ARP

    Ping sends ICMP Echo Request and waits for Echo Reply.

  10. Q10. FTP uses which port for its control connection?

    • A.20
    • B.21(correct answer)
    • C.22
    • D.23

    Port 21 carries commands; port 20 is used for data in active mode.

  11. Q11. Which connectionless protocol is often used for video streaming and online games?

    • A.TCP
    • B.UDP(correct answer)
    • C.FTP
    • D.SMTP

    UDP has low overhead and no retransmission delay.

  12. Q12. Which HTTP status code means “Not Found”?

    • A.200
    • B.301
    • C.404(correct answer)
    • D.500

    200 OK, 301 Moved Permanently, 404 Not Found, 500 Internal Server Error.

  13. Q13. Which HTTP method is normally used to submit form data that creates something new?

    • A.GET
    • B.POST(correct answer)
    • C.HEAD
    • D.OPTIONS

    POST sends data in the request body to create or process a resource.

  14. Q14. Telnet is considered insecure mainly because it:

    • A.Uses UDP
    • B.Sends everything, including passwords, as plain text(correct answer)
    • C.Only works on IPv6
    • D.Has no port number

    Anyone capturing traffic can read it. SSH replaced Telnet for remote login.

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