Computer Knowledge

Computer Networks

2,461 Questions

Computer networks involve the architecture, protocols, and security measures used for digital communication. This collection covers OSI model layers, IP addressing, data transmission, and cryptographic standards. These concepts are vital for the computer knowledge sections of banking and government exams.

OSI model layersNetwork protocolsIP subnet maskingData encryption standardsServer configurationsNetwork commands

Computer Networks Questions

Multiple choice

Which address is an APIPA?

  1. 169.254.0.0/16

  2. 127.0.0.1

  3. 192.168.0.0/16

  4. 168.255.0.0/16
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

APIPA (Automatic Private IP Addressing) addresses are in the 169.254.0.0/16 range. This is used by clients when they cannot reach a DHCP server.

Multiple choice

Which ICMP response would NOT be sent when a packet is dropped by an ACL?

  1. Network administratively prohibited

  2. Host administratively prohibited

  3. Destination network unreachable

  4. Destination port unreachable
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a packet is dropped by an ACL, the router typically sends an ICMP 'Administratively Prohibited' message. 'Destination network unreachable' is generally used for routing table issues, not ACL drops.

Multiple choice

What ICMP response will be sent when the TTL expires?

  1. Destination Unreachable

  2. Source Quench

  3. Redirect Message

  4. Time exceeded
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When an IPv4 packet's Time to Live (TTL) field reaches zero, the router discards the packet and sends an ICMP 'Time Exceeded' message back to the source.

Multiple choice

When would DNS use TCP?

  1. When DNS querys keep failing

  2. When conducting zone transfer

  3. Upon inital DNS connection request

  4. DNS cannot use TCP
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DNS primarily uses UDP for queries. However, it switches to TCP for zone transfers (between servers) or when the response size exceeds the 512-byte UDP limit.

Multiple choice

What ports do FTP use to communicate?

  1. 20/21

  2. 21/22

  3. 22/23

  4. 23/25
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

FTP uses two ports: port 21 for the control connection (commands) and port 20 for the data connection.

Multiple choice

What port does HTTPS run over?

  1. 443

  2. 8080

  3. 80

  4. 3389
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

HTTPS (HTTP Secure) uses TLS/SSL to encrypt traffic and operates over TCP port 443.

Multiple choice

What address is ARP designed to resolve?

  1. Destination MAC

  2. Destination IP

  3. Source MAC

  4. Source IP
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ARP (Address Resolution Protocol) is used to map a known destination IP address to its corresponding physical MAC address on the local network segment.

Multiple choice

What OSI layer does ARP operate at?

  1. 1

  2. 3

  3. 4

  4. 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

ARP operates between the Data Link (Layer 2) and Network (Layer 3) layers, but it is generally considered a Layer 2 protocol because it facilitates the delivery of frames.

Multiple choice

What order are the address fields in the Ethernet 2 Frame header?

  1. Destination IP then Source IP

  2. Source MAC then Destination MAC

  3. Destination MAC then Source MAC

  4. Source IP then Destination IP
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In an Ethernet II frame header, the first 6 bytes are the Destination MAC address, followed by the next 6 bytes which are the Source MAC address.