Networking

Introduction ARP spoofing is an attack technique that has been studied in the network security field for a long time. This attack aims to intercept or modify network traffic by exploiting the structural limitations of the ARP protocol. In this article, we will systematically cover the basic concepts of the ARP protocol, the operational principles of ARP spoofing, actual attack implementation, and methods to defend against it. What is the ARP Protocol? ARP (Address Resolution Protocol) is a protocol responsible for address translation between the network layer (IP) and the data link layer (MAC). Simply put, to communicate on an IP network, you need to know not only the target’s IP address but also its MAC address. This is where ARP comes in. ...

Introduction MAC address (Media Access Control address) is a unique identifier for network devices. For security or privacy reasons, you may need to change this address. In this post, we will explore how to change MAC address in Ubuntu. What is a MAC Address? MAC address is a unique identifier assigned to a Network Interface Card (NIC). This 48-bit (6-byte) address is typically displayed in hexadecimal format as XX:XX:XX:XX:XX:XX. The structure of the address is as follows: ...

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: ...

Introduction SSH (Secure Shell) is a network protocol that allows you to log in to another computer over a network and execute commands on a remote system or transfer files. In this article, we will go through the step-by-step process of installing an SSH server on an Ubuntu system, configuring it to start automatically, and connecting to the SSH server. Installing the SSH Server First, open a terminal and update the list of packages: ...

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: ...