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Network Fundamentals & IP Addressing Flashcards

7 cards from real ICND1 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Network Fundamentals & IP Addressing flashcards as text
  1. Which IPv4 address range is reserved for multicast?

    Answer: 224.0.0.0 – 239.255.255.255

    Class D addresses (224.0.0.0–239.255.255.255) are reserved for multicast group communication.

  2. A network administrator needs at least 50 subnets from 10.0.0.0/8. What is the minimum number of bits to borrow?

    Answer: 6

    2^6 = 64 ≥ 50 subnets; borrowing 5 bits only yields 32, which is insufficient.

  3. Which statement correctly describes full-duplex Ethernet operation?

    Answer: Devices can send and receive simultaneously, eliminating collisions

    Full-duplex allows simultaneous send and receive by using separate wire pairs, eliminating collision domains.

  4. What is the CIDR notation for the subnet mask 255.255.255.192?

    Answer: /26

    255.255.255.192 = 11111111.11111111.11111111.11000000, which has 26 contiguous 1-bits.

  5. Which private IP address range is defined by RFC 1918 for Class A networks?

    Answer: 10.0.0.0 – 10.255.255.255

    RFC 1918 designates 10.0.0.0/8 as the private Class A range.

  6. At which OSI layer does a switch make forwarding decisions based on MAC addresses?

    Answer: Layer 2

    Switches use MAC address tables at Layer 2 (Data Link) to forward frames out the correct port.

  7. Which address is 127.0.0.1 used for?

    Answer: Loopback / localhost testing

    127.0.0.1 is the loopback address used to test the TCP/IP stack on the local host without sending traffic to the network.