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Subnetting 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 Subnetting flashcards as text
  1. You need to divide 192.168.50.0/24 into subnets supporting 60 hosts each. Which mask should you use?

    Answer: /26

    A /26 provides 62 usable hosts (64 - 2), which is the smallest mask that supports 60 hosts.

  2. What is the network address of the subnet containing 172.16.35.200/20?

    Answer: 172.16.32.0

    /20 has a block size of 16 in the third octet; 35 falls in the 32–47 range, so the network is 172.16.32.0.

  3. Which of the following addresses is a valid host in the subnet 10.0.0.128/25?

    Answer: 10.0.0.200

    The subnet 10.0.0.128/25 covers 10.0.0.128–10.0.0.255; only 10.0.0.200 is a valid host (not the broadcast .255).

  4. How many bits must be borrowed from the host portion of a Class B address to create 100 subnets?

    Answer: 7

    2^7 = 128 ≥ 100 and 2^6 = 64 < 100, so 7 bits must be borrowed.

  5. What is the broadcast address of the subnet 10.20.30.64/27?

    Answer: 10.20.30.95

    A /27 has a block size of 32; the subnet starting at .64 ends at .64 + 31 = .95, which is the broadcast.

  6. Which decimal value does the binary octet 11111000 represent in a subnet mask?

    Answer: 248

    11111000 = 128+64+32+16+8 = 248.

  7. A /24 network is subnetted into /28 subnets. How many hosts can each subnet support?

    Answer: 14

    A /28 leaves 4 host bits; 2^4 - 2 = 14 usable host addresses per subnet.