IKM Networking 2 — Questions and Answers
Question 1: What is the standard Ethernet MTU size?
- 512 bytes
- 1024 bytes
- 1500 bytes (Correct answer)
- 9000 bytes
Correct answer: 1500 bytes
The standard Ethernet MTU is 1500 bytes, the maximum payload size of an Ethernet frame.
The standard Ethernet MTU of 1500 bytes has been the default since Ethernet's early days. Jumbo frames can support up to 9000 bytes but require all devices in the path to support them.
Question 2: Which routing protocol uses the Dijkstra algorithm?
- RIP
- OSPF (Correct answer)
- BGP
- EIGRP
Correct answer: OSPF
OSPF is a link-state routing protocol that uses Dijkstra's shortest path first algorithm.
OSPF builds a complete topology map using link-state advertisements and runs Dijkstra's algorithm to compute shortest paths. RIP uses Bellman-Ford, BGP uses path-vector, and EIGRP uses DUAL.
Question 3: What is the purpose of the ARP protocol?
- Resolve domain names to IPs
- Map IP addresses to MAC addresses (Correct answer)
- Assign IPs dynamically
- Encrypt network traffic
Correct answer: Map IP addresses to MAC addresses
ARP resolves IPv4 addresses to MAC addresses on a local network segment.
When a device needs to send a frame on the same subnet, it must know the destination's MAC address. ARP broadcasts a request and the owner responds with its MAC. ARP only works within a broadcast domain.
Question 4: Which topology provides highest fault tolerance but requires the most cabling?
- Star
- Ring
- Full mesh (Correct answer)
- Bus
Correct answer: Full mesh
A full mesh topology connects every device directly to every other device.
In full mesh with n devices, each has n-1 connections, totaling n(n-1)/2 links. This provides maximum redundancy but is expensive and complex for large networks.
Question 5: What is the primary difference between a hub and a switch?
- Hubs are faster
- Switches forward frames by MAC address while hubs broadcast to all ports (Correct answer)
- Hubs support VLANs
- Switches operate at Layer 3
Correct answer: Switches forward frames by MAC address while hubs broadcast to all ports
Switches maintain a MAC address table and forward frames only to the correct port, while hubs broadcast to every port.
A hub is a Layer 1 device that repeats signals to all ports. A switch is a Layer 2 device that learns MAC addresses and forwards frames only to the correct port, reducing collisions.
Question 6: Which port number is used by DNS?
- 22
- 25
- 53 (Correct answer)
- 80
Correct answer: 53
DNS uses port 53 for both UDP (standard queries) and TCP (zone transfers).
DNS primarily uses UDP port 53 for queries. TCP port 53 is used for zone transfers between DNS servers and for responses exceeding the UDP size limit.
IKM Networking 2
What is the standard Ethernet MTU size?