Question

Assume we have an internet with an 8-bit address space. The addresses are equally divided between four networks (N₀ to N₃). The internetwork communication is done through a router with four interfaces (m₀ to m₃). Show the internet outline and the forwarding table (with two columns: prefix in binary and the interface number) for the only router that connects the networks. Assign a network address to each network.

Answer 1

With a given 8-bit address space, four networks (N₀ to N₃) are assigned unique binary prefixes to facilitate routing. A router interfaces (m₀ to m₃) forward packets based on these prefixes, detailed in the forwarding table.

Step-by-step explanation:

In an internet with an 8-bit address space divided into four networks (N₀ to N₃), we can assign a network address to each network by dividing the address space equally. If we consider the address space from 00000000 to 11111111, we can allocate two bits for the network part since we have four networks, leaving six bits for hosts within each network. Therefore, we can assign the following addresses and corresponding binary prefixes:

• N₀: 00xxxxxx (where 'x' represents the host part)
• N₁: 01xxxxxx
• N₂: 10xxxxxx
• N₃: 11xxxxxx

The router's forwarding table will direct packets based on these network prefixes. With interfaces m₀ to m₃ corresponding to networks N₀ to N₃, the forwarding table will look like this:

Prefix (in binary)Interface Number00xxxxxxm₀01xxxxxxm₁10xxxxxxm₂11xxxxxxm₃

This outlines the basic structure of an internet made up of four interconnected networks via a single router, each with its own unique address prefix.