IP Addressing Explained

IP Addressing is a fundamental concept in networking that allows devices to communicate over a network. Understanding IP Addressing is crucial for anyone pursuing the MikroTik Certified Network Associate (MTCNA) certification.

Key Concepts

IP Address: A unique identifier assigned to each device on a network.
IPv4: The most widely used IP version, consisting of 32 bits.
IPv6: The newer IP version, consisting of 128 bits, designed to address the limitations of IPv4.
Subnet Mask: A 32-bit number that divides an IP address into network and host portions.
CIDR Notation: A method of representing IP addresses and their subnet masks.

IP Address

An IP Address is a unique string of numbers separated by periods that identifies each computer using the Internet Protocol to communicate over a network. For example, an IPv4 address might look like this: 192.168.1.1.

IPv4

IPv4 addresses are 32-bit numbers, typically represented in decimal format, divided into four octets. Each octet can range from 0 to 255. For instance, the address 192.168.1.1 is broken down as follows:

This format allows for approximately 4.3 billion unique addresses, which is increasingly insufficient for the growing number of devices connected to the internet.

IPv6

IPv6 addresses are 128-bit numbers, represented in hexadecimal format, divided into eight groups of four hexadecimal digits. For example, an IPv6 address might look like this: 2001:0db8:85a3:0000:0000:8a2e:0370:7334.

IPv6 was introduced to overcome the limitations of IPv4 by providing a vastly larger address space, allowing for approximately 340 undecillion unique addresses.

Subnet Mask

A subnet mask is used to divide an IP address into network and host portions. For example, with an IP address of 192.168.1.1 and a subnet mask of 255.255.255.0, the first three octets (192.168.1) represent the network, and the last octet (1) represents the host.

Subnet masks help in organizing networks into smaller, manageable segments, improving network performance and security.

CIDR Notation

CIDR (Classless Inter-Domain Routing) notation is a compact representation of an IP address and its associated routing prefix. For example, the CIDR notation for the IP address 192.168.1.1 with a subnet mask of 255.255.255.0 is written as 192.168.1.1/24.

The "/24" indicates that the first 24 bits of the IP address are the network portion, and the remaining 8 bits are the host portion.

Examples

Consider a small office network with the following details:

IP Address: 192.168.1.10
Subnet Mask: 255.255.255.0
CIDR Notation: 192.168.1.10/24

In this example, the network portion is 192.168.1, and the host portion is 10. This configuration allows for 254 devices to be connected to the same network segment.

For larger networks, IPv6 addresses are used. For instance:

IPv6 Address: 2001:0db8:85a3:0000:0000:8a2e:0370:7334
Subnet Mask: /64
CIDR Notation: 2001:0db8:85a3:0000:0000:8a2e:0370:7334/64

In this case, the first 64 bits represent the network, and the remaining 64 bits represent the host, providing an enormous number of possible host addresses.

Understanding these concepts is essential for configuring and managing networks using MikroTik devices, which is a key part of the MTCNA certification.