Classful Addressing (Solved Question 2) | Summary and Q&A

TL;DR

Learn how to determine the number of addresses, as well as the first and last address, in a class B network.

Key Insights

• 🔒 In a class B network, the network portion consists of the first two octets of an IP address, while the host portion consists of the last two octets.
• 📊 A class B network allows for a possibility of 65,534 usable IP addresses or hosts.
• 🔍 The first address and last address of a class B network are reserved, resulting in a maximum of 65,534 usable addresses.
• ⚙️ The default subnet mask for a class B network is 255.255.0.0, indicating that the first two octets are for the network portion and the remaining two octets are for the host portion.
• 💡 To determine the class of an IP address, check if the first octet falls between 128 and 191. An IP address with the first octet of 185 is classified as class B.
• 🌐 In a class B network, the network address is fixed at 185.28.0.0, while the broadcast address is 185.28.255.255.
• 🔢 A class B network has a maximum of 65,536 possible addresses, based on the 16 bits allocated for the host portion.
• 💻 In a class B network, there are 65,534 usable addresses for hosts, excluding the network address and the broadcast address.

Transcript

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Questions & Answers

Q: How can you determine the number of addresses and the first and last address in a class B network?

To find the number of addresses, first identify the class of the IP address. In class B, the first two octets are for the network portion. The first address is the network address, while the last address is the broadcast address. Using the formula 2^16, subtract 2 to get the total number of usable addresses.

Summary & Key Takeaways

• There are five classes of IP addresses, and this video focuses on class B networks.

• In a class B network, the first two octets represent the network portion, and the last two octets represent the host portion.

• Class B networks have a possibility of 2^16 hosts and 2^14 networks, with 65,534 usable addresses.