IP

The concept of a subnet mask was introduced in the evolution of TCP/IP protocols around 1985. The early internet used a classful addressing system (A, B, C classes), which was proving to be too rigid, and inefficient for IP address allocation. Subnet masks came into the picture to address this issue. History and Need for Subnet Masks In the early days of the internet, the class of an IP address was determined by looking at just the first octet (byte) of the address: ...

CIDR (Classless Inter-Domain Routing) was introduced to overcome the limitations of the existing class-based IP allocation. It allows flexible allocation of IP addresses as needed, preventing address waste. CIDR Notation and Structure CIDR represents the network bit count with the ‘/’ symbol followed by the IP address: 192.168.1.0/24 Network part: 192.168.1 (24 bits) Host part: Last 8 bits Available IPs: 254 192.168.1.0/25 Network part: 192.168.1.0 (25 bits) Host part: Last 7 bits Available IPs: 126 Relation with Subnet Mask CIDR prefixes correspond one-to-one with subnet masks: ...

Basic Structure of an IP Address An IP address is broadly divided into two parts: a ’network portion’ that distinguishes between networks, and a ‘host portion’ that identifies individual devices within that network. It’s similar to the address system of an office building. If ‘123 Main Street, New York City’ is the network portion, then ‘Suite 301, 3rd Floor’ is the host portion. Devices that share the same network portion belong to the same network. ...

Introduction In this article, we will discuss how to configure a static IP on Ubuntu 24.04 LTS. Static IP addresses are helpful for streamlining network management and ensuring reliable connections to your servers. We will cover the steps for configuring an IP address using netplan. Additionally, we will discuss the TUI (nmtui) and CLI (nmcli) methods for setting up a static IP address using NetworkManager. Benefits of a Static IP Consistency: Static IP addresses ensure stability by always using the same IP for network configurations. Remote Access: They simplify connecting to your server externally since the IP address remains consistent. Hosting Services: Static IPs are crucial for running services such as web servers and mail servers. Firewall Configuration: IP-based firewall rules are easier to manage with static IPs. Network Troubleshooting: Static IPs simplify diagnosing and resolving network issues. Methods 1. Configure a Static IP Using netplan (CLI) Open the Network Configuration File Ubuntu 24.04 LTS uses netplan to manage network configurations. Open a terminal window and run the following command to open your network configuration file: ...