Class B IP addresses are a category of IP addresses defined by the Internet Protocol (IP), which is a set of rules that dictate how data is sent and received over the internet.
History and Origin
The concept of Class B IP addresses originated from the initial IP address classification system known as classful networking. This system was introduced in the early days of the internet around the 1980s with the development of IPv4 (Internet Protocol version 4) as a means of managing the allocation and distribution of IP addresses.
Detailed Information
Class B IP addresses are one of the five classes of IP addresses (Class A, B, C, D, and E) that were used in the early stage of the internet. In classful networking, each class uses a distinct network address and host addressing scheme, with Class B IP addresses falling between Class A and Class C in terms of size and scale.
Each Class B network includes a 16-bit network prefix, followed by a 16-bit host number. The IP address range for Class B is from 128.0.0.0 to 191.255.255.255. This means that a Class B network can have up to 65,534 hosts (2^16 minus 2 for the network address and broadcast address).
Internal Structure and Functionality
Class B IP addresses have a two-octet network portion and a two-octet host portion. In binary terms, the first two octets are the network address, and the last two octets are the host address. For example, in the IP address 150.150.1.1, “150.150” is the network address, and “1.1” is the host address.
The first two bits of the first octet in a Class B address are always 10. This leaves 14 bits for the network address, offering a total of 16,384 (2^14) possible network addresses.
Key Features
Some of the key features of Class B IP addresses include:
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A large number of host addresses: Class B networks can accommodate a substantial number of host addresses, making them ideal for medium to large-sized organizations.
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Class B addresses are globally unique: Each Class B IP address is unique across the entire internet, ensuring no conflicts or overlaps.
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Binary identifier: The initial bits of Class B addresses are set to 10, distinguishing them from other classes.
Types of Class B IP Address
The Class B IP addresses can be categorized based on their application:
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Public Class B IP Address: These are globally unique and are assigned by the Internet Assigned Numbers Authority (IANA) and Regional Internet Registries (RIRs). They are used for communication over the internet.
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Private Class B IP Address: These are reserved for private networks and are not routable on the internet. The reserved range for private Class B IP addresses is from 172.16.0.0 to 172.31.255.255.
Usage and Associated Problems
Class B IP addresses are typically used by medium to large-sized organizations that require a large number of IP addresses for their networked devices. However, the classful networking system, including Class B addresses, has been largely replaced by Classless Inter-Domain Routing (CIDR) due to the issue of IP address exhaustion. CIDR allows for more efficient allocation of IP addresses.
Comparisons with Similar Terms
| Item | Class A | Class B | Class C |
|---|---|---|---|
| First Octet Range | 1-126 | 128-191 | 192-223 |
| Network Bits | 8 | 16 | 24 |
| Host Bits | 24 | 16 | 8 |
| Number of Networks | 126 | 16,384 | 2,097,152 |
| Hosts per Network | 16,777,214 | 65,534 | 254 |
Future Perspectives and Technologies
The introduction of IPv6, which provides a significantly larger address space, has solved the problem of IPv4 address exhaustion. Despite this, many organizations continue to use IPv4, including Class B addresses, due to the cost and complexity of transitioning to IPv6.
Association with Proxy Servers
Proxy servers can be associated with Class B IP addresses in several ways. They can use Class B IP addresses to forward requests and responses between servers and clients. Additionally, using a range of Class B IP addresses can help proxy servers to distribute the load, increase redundancy, and improve the anonymity of their users.
