Network Fundamentals

A comprehensive, technical reference for network engineers.
Protocols, standards, and troubleshooting guides.

🔌 Ethernet (802.3)

The physical and data link layer foundation. Frame structures, MAC addressing, media types, and Layer 1 troubleshooting.

🌐 IPv4 / IPv6

Packet headers, addressing classes, CIDR subnetting, fragmentation, and MTU analysis.

📦 TCP / UDP

Transport layer mechanics. Flow control, windowing, 3-way handshake state machines, and reliability.

🔀 Routing Protocols

OSPF, EIGRP, and BGP. Link-state algorithms, metric calculations, convergence, and route redistribution.

🔄 Switching (L2)

VLANs, 802.1Q tagging, Spanning Tree Protocol (STP/RSTP), and ARP tables.

🔒 Network Security

ACLs, VPNs (IPsec/SSL), Firewalls, and 802.1X authentication standards.

☁️ Data Center & Cloud

Modern Leaf-Spine architectures, VXLAN overlays, EVPN control planes, and Software-Defined Networking (SDN).

🤖 Automation & NetDevOps

Python (Netmiko/Nornir), Ansible Playbooks, REST APIs, JSON/YAML data models, and Infrastructure as Code (IaC).

🌍 WAN & SD-WAN

MPLS Layer 3 VPNs, Label Switched Paths, BGP Route Targets, and the evolution to Application-Aware SD-WAN overlays.