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GCIA · Question #29

Which of the following is a valid IP address for class B Networks?

The correct answer is D. 172.157.88.3. Class B networks span the 128.0.0.0 to 191.255.255.255 range, defined by the first two bits being '10'. Only 172.157.88.3 falls within this range.

Network Traffic Analysis & Protocol Review

Question

Which of the following is a valid IP address for class B Networks?

Options

  • A225.128.98.7
  • B80.33.5.7
  • C212.136.45.8
  • D172.157.88.3

How the community answered

(65 responses)
  • A
    15% (10)
  • B
    3% (2)
  • C
    6% (4)
  • D
    75% (49)

Why each option

Class B networks span the 128.0.0.0 to 191.255.255.255 range, defined by the first two bits being '10'. Only 172.157.88.3 falls within this range.

A225.128.98.7

225.128.98.7 has a first octet of 225, which falls in the 224-239 range reserved for Class D multicast addresses, not Class B.

B80.33.5.7

80.33.5.7 has a first octet of 80, which falls in the 1-126 range reserved for Class A networks.

C212.136.45.8

212.136.45.8 has a first octet of 212, which falls in the 192-223 range reserved for Class C networks.

D172.157.88.3Correct

172.157.88.3 is a valid Class B address because the first octet (172) falls within the Class B range of 128 to 191. Class B networks are identified by the leading two bits '10' in binary, covering 128.0.0.0 through 191.255.255.255. The 172.x.x.x block is a well-known Class B space, with 172.16.0.0 to 172.31.255.255 reserved for private use under RFC 1918.

Concept tested: IPv4 classful addressing and range identification

Source: https://learn.microsoft.com/en-us/troubleshoot/windows-client/networking/tcpip-addressing-and-subnetting

Topics

#IP address classes#class B addressing#IPv4 ranges#subnetting

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