An administrator needs to add the following networks to a QRadar network hierarchy as a single Classless Inter-Domain Routin (CIDR) range: 192.168.64.0/24 192.168.65.0/24 192.168.66.0/24…

Question

Options

• ANetwork 192.168.66.0 with subnet mask 255.255.252.0
• BNetwork 192.168.64.0 with subnet mask 255.255.252.0
• CNetwork 192.168.64.0 with subnet mask 255.255.255.0
• DNetwork 192.168.66.0 with subnet mask 255.255.252.0

• A
  15% (8)
• B
  72% (38)
• C
  9% (5)
• D
  4% (2)

Explanation

Option B is correct because the supernet must start at the lowest network address in the group (192.168.64.0), and combining four /24 subnets requires borrowing 2 bits from the subnet boundary (2² = 4 subnets), shifting the prefix from /24 to /22 - which equals subnet mask 255.255.252.0.

Why the distractors fail:

• A and D (identical in this question, likely a typo) use 192.168.66.0 as the network address - this is wrong because a supernet's address must be the lowest address in the block, which is .64.0, not .66.0.
• C uses the correct network address (192.168.64.0) but the wrong mask (255.255.255.0 = /24), which only covers a single /24 subnet rather than all four.

Memory tip: Think of supernetting as "rounding down and expanding." The network address always rounds down to the lowest in the group, and for every power-of-2 subnets you're collapsing (4 = 2²), you remove that many bits from the mask - so /24 minus 2 bits = /22 = 255.255.252.0.

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