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SSCP · Question #1089

There are 5 classes of IP addresses available, but only 3 classes are in common use today, identify the three: (Choose three)

The correct answer is A. Class A: 1-126 B. Class B: 128-191 C. Class C: 192-223. The three classes of IPv4 addresses commonly used for assigning to hosts on networks are Class A, Class B, and Class C.

Submitted by saadiq_pk· Apr 18, 2026Network and Communications Security

Question

There are 5 classes of IP addresses available, but only 3 classes are in common use today, identify the three: (Choose three)

Options

  • AClass A: 1-126
  • BClass B: 128-191
  • CClass C: 192-223
  • DClass D: 224-255
  • EClass E: 0.0.0.0 - 127.0.0.1

How the community answered

(64 responses)
  • A
    91% (58)
  • D
    3% (2)
  • E
    6% (4)

Why each option

The three classes of IPv4 addresses commonly used for assigning to hosts on networks are Class A, Class B, and Class C.

AClass A: 1-126Correct

Class A IP addresses are defined by a first octet range of 1-126 and are used for very large networks.

BClass B: 128-191Correct

Class B IP addresses are defined by a first octet range of 128-191 and are typically used for medium-sized networks.

CClass C: 192-223Correct

Class C IP addresses are defined by a first octet range of 192-223 and are generally used for smaller networks.

DClass D: 224-255

Class D addresses (224-239) are reserved exclusively for multicast communication and are not assigned to individual hosts or for general unicast use.

EClass E: 0.0.0.0 - 127.0.0.1

Class E addresses (240-255) are reserved for experimental or research purposes and are not publicly routable or used for general assignment; additionally, the listed range 0.0.0.0 - 127.0.0.1 incorrectly includes the Class A loopback network.

Concept tested: IPv4 address classes and ranges

Source: https://www.cisco.com/c/en/us/support/docs/ip/routing-information-protocol-rip/16448-ipaddress.html

Topics

#IP Addressing#Network Protocols#TCP/IP#Networking Fundamentals

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