Tutorials · Networking
Networking tutorials
OSI and TCP/IP, routing, switching, VLANs and ACLs, explained with configurations you can try.
● 36 free guidesNetworking lessons36 guides
What Are the Internet and Networking? A Beginner’s Guide
Internet and networking basics for beginners: what a network is, LAN, MAN and WAN, how the internet began,…
3 min read 02Network Devices and Network Topologies Explained
Network devices and topologies explained: modems, NICs, hubs, switches, routers, gateways and firewalls, plus bus, star, ring, mesh…
3 min read 03What Is a MAC Address? Format, Types and Why We Need It
What a MAC address is, its format and OUI, MAC address types (unicast, multicast, broadcast), MAC vs IP,…
3 min read 04What Is an IP Address? IPv4 and IPv6 Explained
What an IP address is, how IPv4 and IPv6 work, binary conversion, address classes and CIDR, private ranges,…
3 min read 05Internet and Web Technology Basics: Internet vs Web, URLs and DNS
Internet and web technology basics: the internet vs the web, URI vs URL, how DNS works, who governs…
4 min read 06Top Networking Certifications in 2026: Which One Should You Get?
A guide to the top networking certifications: CompTIA Network+, Cisco CCNA, CCNP and CCIE, Juniper and cloud networking,…
3 min read 07The OSI Model Explained: 7 Layers, Protocols and Devices
The OSI model explained layer by layer: what each of the 7 layers does, example protocols and devices,…
3 min read 08OSI Model Analogy: The 7 Layers Explained with a Simple Example
An easy OSI model analogy: follow a bicycle sent by courier from Bangalore to Mumbai to see what…
5 min read 09Types of Transmission Media in Networking: Guided and Unguided
Types of transmission media in networking: twisted pair, coaxial and fibre, radio, microwave and infrared, plus straight-through, crossover…
3 min read 10The TCP/IP Model Explained: Layers, Protocols and Data Flow
The TCP/IP model explained: its four layers, key protocols at each layer, encapsulation, how it compares with OSI,…
3 min read 11What Is a Router? Router Components and Cisco IOS Basics
What is a router? Learn router components (CPU, RAM, NVRAM, flash, ROM), the boot process and the basics…
5 min read 12What Is a Routing Protocol? Distance Vector, Link State and Path Vector
What a routing protocol is and how the main types compare: distance vector, link state, advanced distance vector…
3 min read 13Routing Protocol Categories: Autonomous Systems, IGP, EGP and BGP
Routing protocol categories explained: autonomous systems and ASNs, interior gateway protocols (IGP), exterior gateway protocols (EGP) and BGP.
3 min read 14Routing Metrics, Cost and Administrative Distance Explained
Administrative distance vs routing metrics: how routers choose the best path, what cost means in OSPF and RIP,…
4 min read 15What Is Routing? Static, Default and Dynamic Routing Explained
What routing is and the main types of routing: static, default and dynamic routing, with Cisco configuration examples,…
3 min read 16Routing Information Protocol (RIP): How It Works, Timers and Configuration
Routing Information Protocol (RIP) explained: hop count, RIPv1 vs RIPv2 vs RIPng, timers, loop prevention, Cisco configuration and…
3 min read 17What Is OSPF? How Open Shortest Path First Works, with Cisco Configuration
OSPF explained: how Open Shortest Path First works, hello packets, neighbour states, areas, DR and BDR, cost, and…
3 min read 18What Is EIGRP? How It Works, Packet Types and Cisco Configuration
EIGRP explained: how Cisco's Enhanced Interior Gateway Routing Protocol works, DUAL, successors, the metric, packet types and configuration.
3 min read 19Access Control List (ACL) in Networking: How ACLs Filter Traffic
Access control list in networking explained: how ACLs work, how routers process them, wildcard masks, inbound vs outbound,…
3 min read 20Types of ACLs in Networking: Standard, Extended, Named and More
The main types of ACLs in networking explained: standard, extended and named ACLs, plus time-based, reflexive and IPv6…
3 min read 21Standard ACLs: Permit and Deny Hosts, Networks and Subnets (Cisco)
Standard ACL examples: permit or deny specific hosts, networks and subnets using wildcard masks, with Cisco configuration commands.
5 min read 22Extended ACLs: Permit and Deny by Address, Protocol and Port (Cisco)
Extended ACL examples: permit or deny traffic by source and destination address, protocol and port, with Cisco configuration…
5 min read 23Network ACL Questions and Answers: Practical Cisco Examples
Practical ACL questions and answers: write Cisco access lists for real scenarios, like permitting email only between two…
4 min read 24What Is a Network Switch? Types and Basic Cisco Switch Configuration
What a network switch is, how it forwards frames, the main switch types, and a basic, secure network…
3 min read 25What Is a VLAN? Benefits and Step-by-Step VLAN Configuration on Cisco
What a VLAN is, why networks use VLANs, and step-by-step VLAN configuration on Cisco switches: creating VLANs, access…
3 min read 26Inter-VLAN Routing Configuration: Legacy, Router-on-a-Stick and Layer 3 Switch
Inter-VLAN routing configuration on Cisco: legacy routing, router-on-a-stick with 802.1Q subinterfaces, and SVIs on a Layer 3 switch,…
3 min read 27What Is VLAN Trunking Protocol (VTP)? Modes, Versions and Configuration
VLAN Trunking Protocol (VTP) explained: server, client, transparent and off modes, versions 1 to 3, the revision risk…
4 min read 28What Is AAA in Networking? Authentication, Authorization and Accounting
AAA in networking explained: authentication, authorization and accounting, RADIUS vs TACACS+, and a working Cisco AAA configuration with…
4 min read 29What Is BGP? Border Gateway Protocol Explained (with Cisco Configuration)
Border Gateway Protocol (BGP) explained: how internet routing between autonomous systems works, BGP path selection and common use…
6 min read 30What Is DHCP and How to Configure It on a Cisco Router
What DHCP is and how to configure DHCP on a Cisco router: enable the DHCP server, create an…
4 min read 31k0t VPN Credentials Leak: 70,000+ Firewall Logins Exposed
The k0t VPN credentials leak exposed 70,000+ firewall logins via FortiGate, FortiWeb and GlobalProtect. Patch, rotate, hunt IOCs…
10 min read 32VeloCloud Vulnerability CVE-2026-114625 Exploited: Patch Now
Exploited VeloCloud vulnerability CVE-2026-114625 lets any VCO user become operator. Fixed versions, IOCs, log checks and a patch…
9 min read 33Ivanti Connect Secure Zero-Day CVE-2026-104935: What to Do
An exploited Ivanti Connect Secure vulnerability (CVE-2026-104935) gave attackers root. Fixed versions, IOCs, reset steps and the unpatched…
10 min read 34FortiMail Vulnerability CVE-2026-104286 Exploited: Patch Now
Exploited FortiMail vulnerability CVE-2026-104286 lets attackers write files without login. Fixed versions, IBE workaround, IOCs and log checks.
10 min read 35NetScaler CVE-2026-88771 Exploited: Patch, Check, Clean Up
NetScaler vulnerability CVE-2026-88771 was exploited as a zero-day. See the fixed builds, the later SAML zero-days and how…
10 min read 36October 2026 Exploited Vulnerabilities: CISA KEV Patch Roundup
Exploited vulnerabilities October 2026: PAN-OS, Cisco email gateway, SonicWall SMA1000, SiteGuard, Siemens and Apple. Fixed versions and actions.
10 min readNeed this done properly on your systems?
We secure servers, test websites and get businesses ready for ISO 27001.