Linux Networking

Linux Networking refers to the comprehensive set of tools, configuration files, and kernel subsystems within the Linux operating system dedicated to managing network communication. It provides a powerful and flexible implementation of the TCP/IP protocol suite, allowing administrators to configure network interfaces, define routing rules, implement sophisticated firewalls using utilities like `iptables` or `nftables`, and deploy a wide range of network services. Due to its stability, open-source nature, and extensive configurability, Linux networking is a foundational element for a vast number of servers, routers, and embedded devices that power the internet and private networks.

1. Introduction to Linux Networking
   1. Linux Networking Architecture Overview
      1. Historical Context and Evolution
      2. Comparison with Other Operating Systems
      3. Kernel Space vs User Space Networking
   2. TCP/IP Model in Linux Context
      1. Physical Layer
         1. Network Interface Hardware
         2. Device Drivers and Kernel Interaction
         3. Hardware Detection and Management
      2. Data Link Layer
         1. Ethernet Frame Structure
         2. MAC Addressing
         3. Address Resolution Protocol (ARP)
         4. VLAN Tagging
         5. Link Layer Protocols
      3. Network Layer
         1. IP Addressing and Packet Routing
         2. Internet Control Message Protocol (ICMP)
         3. Packet Fragmentation and Reassembly
         4. IPv4 vs IPv6 Processing
      4. Transport Layer
         1. Transmission Control Protocol (TCP)
         2. User Datagram Protocol (UDP)
         3. Port Numbers and Socket Pairs
         4. Connection Establishment and Teardown
         5. Flow Control and Congestion Control
      5. Application Layer
         1. Common Network Services
         2. Client-Server Model
         3. Socket Programming Interface
   3. Linux Kernel Networking Components
      1. Network Stack Architecture
      2. Socket API
         1. Socket Types
         2. System Calls
         3. Socket States
      3. Network Device Drivers
         1. Driver Loading and Unloading
         2. Driver Configuration
         3. Driver Troubleshooting
      4. Protocol Stack Implementation
         1. Kernel Modules for Protocols
         2. Modular vs Monolithic Stacks
   4. Essential Configuration Files
      1. /etc/hosts
         1. Hostname to IP Mapping
         2. Syntax and Usage
         3. Priority in Name Resolution
      2. /etc/resolv.conf
         1. DNS Resolver Configuration
         2. Nameserver Entries
         3. Search Domains
      3. /etc/nsswitch.conf
         1. Name Service Switch Configuration
         2. Resolution Order Methods
      4. Distribution-Specific Files
         1. RHEL/CentOS Network Scripts
         2. Debian/Ubuntu Interfaces File
         3. Modern Ubuntu Netplan