Networking
Network Fundamentals
Start with the basic job of a network and how devices communicate.
Read →LAN, WAN & Common Network Types
Understand LANs, WANs and where common network types fit.
Read →Network Topologies
Learn star, point-to-point and redundant topology ideas without memorising pictures.
Read →OSI Model — Easy & Practical
Use the seven OSI layers as a troubleshooting model, not just exam theory.
Read →TCP/IP Model
See how the practical TCP/IP model groups networking functions.
Read →Encapsulation & De-encapsulation
Understand what happens to data as it moves down and up the network stack.
Read →Ethernet Fundamentals
Learn the basic role of Ethernet in wired LAN communication.
Read →MAC Addresses
Understand 48-bit MAC addresses and their role on the local link.
Read →Switching Fundamentals
Learn how a Layer-2 switch forwards Ethernet frames.
Read →MAC Address Table
Read the switch table that maps learned MAC addresses to interfaces.
Read →VLAN Fundamentals
Understand why VLANs create separate Layer-2 broadcast domains.
Read →802.1Q Trunking
Understand how one link carries traffic for multiple VLANs.
Read →Access Ports
Learn how endpoint switch ports are placed into a VLAN.
Read →Inter-VLAN Routing
See why Layer-3 routing is required between VLANs.
Read →Router-on-a-Stick
Route multiple VLANs through router subinterfaces over a trunk.
Read →Spanning Tree Protocol
Understand how STP prevents Layer-2 loops while keeping redundancy.
Read →STP Root Election & Port Roles
Go deeper into how STP chooses the root and forwarding paths.
Read →RSTP Basics
Understand why Rapid STP converges faster than classic STP.
Read →EtherChannel
Bundle multiple Ethernet links into one logical channel.
Read →IPv4 Addressing
Understand IPv4 addresses, prefixes and how hosts decide local versus remote.
Read →Subnet Masks & Prefix Length
Learn what /24, /27 and other prefixes actually tell a host.
Read →Subnetting Fundamentals
Learn why subnetting exists before doing subnet maths.
Read →Subnetting Step-by-Step
Use a repeatable method to solve common IPv4 subnet questions.
Read →Public vs Private IPv4 Addresses
Know the private IPv4 ranges and why edge translation is common.
Read →Default Gateway
Understand exactly when a host uses its gateway.
Read →ARP — IP to MAC Resolution
See how IPv4 devices discover the MAC address needed for local delivery.
Read →Dynamic ARP Inspection
Validate ARP traffic using trusted Layer-2 information.
Read →DHCP & DORA
Learn how clients automatically receive IPv4 configuration.
Read →DHCP Relay
Serve DHCP clients when the server is on another routed network.
Read →DHCP Snooping
Protect switched networks from unwanted DHCP server behaviour.
Read →DNS — Name Resolution
Understand how names are resolved and why DNS failures look like internet failures.
Read →ICMP
Understand control and diagnostic messaging in IP networks.
Read →Ping & Traceroute
Use ping and traceroute correctly instead of treating them as magic commands.
Read →TCP Fundamentals
Understand reliable connection-oriented transport.
Read →UDP Fundamentals
Understand lightweight connectionless transport and its trade-offs.
Read →TCP vs UDP
Compare TCP and UDP by behaviour, not by “good versus bad”.
Read →TCP Three-Way Handshake
See what SYN, SYN-ACK and ACK mean in a new TCP connection.
Read →Ports & Common Protocols
Understand why transport ports matter in access control and troubleshooting.
Read →Routing Fundamentals
Learn how routers forward packets between IP networks.
Read →Reading the Routing Table
Understand route sources, prefixes, next hops and the best-match idea.
Read →Static Routing
Configure and reason about manually defined routes.
Read →Default Routing
Use a catch-all route when no more-specific destination is known.
Read →Dynamic Routing Concepts
Understand why routing protocols exchange reachability information.
Read →OSPF Fundamentals
Learn the core OSPF ideas: neighbours, link-state information and SPF.
Read →OSPF Neighbours & Adjacency
Understand what must happen before OSPF routes can be exchanged normally.
Read →EIGRP Fundamentals
Understand EIGRP neighbours and route learning at foundation level.
Read →ACL Fundamentals
Understand ordered permit/deny traffic matching.
Read →Standard vs Extended ACLs
Know what each ACL type can match and where placement matters.
Read →NAT Fundamentals
Understand address translation at network edges.
Read →PAT / NAT Overload
See how many inside sessions can share one translated address.
Read →IPv6 Fundamentals
Start IPv6 with address format and key differences from IPv4.
Read →IPv6 Neighbor Discovery
Understand the IPv6 mechanism that replaces several IPv4 local-link functions.
Read →SSH for Network Device Management
Use encrypted remote CLI access instead of plaintext management.
Read →NTP & Syslog
Keep device time consistent and collect useful event logs.
Read →CDP & LLDP
Discover directly connected network neighbours.
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