§2023-12-10

This is the IP layouts of YuShei

¶ decimal and hex representation

¶Network Address and Broadcast address

In a TCP/IP network, each device is assigned an IP address to identify itself on the network. When you define a subnet using CIDR notation, the network address and the broadcast address are two specific addresses within that subnet.

• Network Address:

The network address is the address that represents the entire network or subnet. It is the address with all host bits set to zero. For example, in the CIDR notation "192.168.16.0/20," the network address is "192.168.16.0." All devices within this subnet share the same network address as the first part of their IP address.

• Broadcast Address:

The broadcast address is used to send data to all devices within a specific network or subnet. It is the address with all host bits set to one.

Using the same example, in the CIDR notation "192.168.16.0/20," the broadcast address is "192.168.31.255." When a device sends data to this address, it is broadcast to all devices in the "192.168.16.0/20" subnet. In summary:

Network Address: Represents the entire network, with host bits set to zero. Broadcast Address: Used to broadcast data to all devices within the network, with host bits set to one. It's worth noting that in many networking environments, the network address and broadcast address are often reserved and not assignable to individual devices. For example, in a subnet with the network address "192.168.16.0" and a subnet mask of "/20," the usable host addresses for devices would typically be in the range of "192.168.16.1" to "192.168.31.254," excluding the network address and broadcast address.

¶Network Portion nad Host portion of a network address

In IP (Internet Protocol) addressing, an IP address is divided into two main parts: the network portion and the host portion. The host portion is further divided into network and host bits. Let's break down the terms:

• Network Portion:

This part of the IP address identifies the network to which a device belongs. The network portion is used by routers to determine how to route data between different networks.

• Host Portion:

This part of the IP address identifies a specific device within the network. The host portion is used by devices within the same network to communicate with each other.

• Host Bits:

The host bits are the bits in the IP address that are left after allocating the network bits. The number of host bits determines the number of unique host addresses that can exist within a network. In CIDR (Classless Inter-Domain Routing) notation, the subnet mask is used to specify how many bits are allocated to the network portion and how many bits are allocated to the host portion. For example:

If you have an IP address like 192.168.1.1 with a subnet mask of 255.255.255.0 (or /24 in CIDR notation), the first 24 bits are allocated to the network, and the last 8 bits are for hosts. In binary, the subnet mask looks like 11111111.11111111.11111111.00000000, where the first 24 bits are set to 1 (network bits) and the last 8 bits are set to 0 (host bits).

If you have an IP address like 192.168.1.1 with a subnet mask of 255.255.255.128 (or /25 in CIDR notation), the first 25 bits are allocated to the network, and the last 7 bits are for hosts. In binary, the subnet mask looks like 11111111.11111111.11111111.10000000, where the first 25 bits are set to 1 (network bits) and the last 7 bits are set to 0 (host bits).

The allocation of bits to the network and host portions allows for the creation of subnets and helps manage IP address space efficiently within a network.