Networking
How data travels: OSI and TCP/IP, IP addressing and subnetting, routing, DNS, HTTP, TLS and troubleshooting
- 8 lessons
- 6 hours
- Beginner
- Graded labs: 24
What you will learn
- Explain what each OSI and TCP/IP layer does and place protocols (Ethernet, IP, TCP, HTTP) on the right layer.
- Convert between binary and dotted-decimal and compute the network, broadcast and usable host range of any IPv4 CIDR block.
- Plan a subnetting scheme (VLSM) for an office from host-count requirements without wasting addresses.
- Explain how switches, VLANs and ARP deliver frames inside a LAN, and predict a router's next hop with longest-prefix match.
- Trace a DNS lookup from resolver to root, TLD and authoritative server and diagnose failures with dig.
- Walk through a TCP handshake and a TLS connection and read HTTP request and response headers.
- Troubleshoot connectivity layer by layer with ping, traceroute, ss and a packet capture.
- Design a segmented network with default-deny firewall rules, NAT, a VPN and WPA3 Wi-Fi, and name the attack each control stops.
How you are assessed
Networking mastery is calculation plus diagnosis: you subnet by hand, predict routing decisions, and explain a failing connection layer by layer. Graded labs check your arithmetic automatically.
- Complete every Foundations lesson
- Average on first-try quizzes: at least 70%
- Graded lab exercises to pass: 2
- Challenges to solve: 1
- Lessons
Learn the model
Complete every foundations lesson: layers, IP addressing and subnetting, TCP and UDP, and DNS, HTTP and TLS.
- Quizzes
Explain the layers
Average at least 70% on first-try quizzes about protocols, handshakes and name resolution.
- Lab exercises
Do the arithmetic
Pass graded labs on CIDR calculation and longest-prefix routing with visible tests.
- Challenges
Read the packets
Solve one networking challenge such as decoding a captured exchange.
Curriculum
How data travels
Layers, addressing, transport, and the DNS, HTTP and TLS steps behind every web page: the core model.
- 1.The OSI & TCP/IP Models — How Data Travels
The layered models that explain how a message travels from one application to another: physical links, frames, packets, segments and data. Learn what each layer does, which protocols and devices live there, and how encapsulation wraps your data on the way down and unwraps it on the way up.
40 min 1 quiz Graded labs: 3 - 2.IP Addressing & Subnetting — Carving Up the Network
IPv4 and IPv6 addresses, private vs public ranges, CIDR notation, subnet masks and gateways. Learn to work out a network address, broadcast address and usable host range by hand, split a network into subnets (VLSM), and see how routers choose a route with longest-prefix match.
41 min 1 quiz Graded labs: 3 - 3.TCP, UDP & Ports — Conversations Between Programs
How the transport layer turns raw packet delivery into conversations between programs. Covers ports and sockets, the TCP three-way handshake, reliability, flow and congestion control, connection teardown, the Internet checksum, and when UDP is the better choice.
42 min 1 quiz Graded labs: 3 - 4.DNS, HTTP & TLS — From a URL to a Page
What happens between typing a URL and seeing a page: DNS resolution and record types, the HTTP request/response format, status codes and headers, and how TLS authenticates servers with certificates and encrypts the conversation.
46 min 1 quiz Graded labs: 3
Running a network
Switching and routing, troubleshooting tools, Wi-Fi, VPNs and firewalls.
- 5.Routing & Switching — How Packets Find Their Way
How traffic moves inside and between networks: Ethernet switches and MAC learning, VLANs, ARP, static and dynamic routing, and the idea behind protocols such as OSPF and BGP. This is the core knowledge behind network engineering roles.
43 min 1 quiz Graded labs: 3 - 6.Troubleshooting Tools — Finding Where a Connection Breaks
A practical method for finding where a connection breaks: check the link, the address, the route, the name and the service in turn. Learn ping, traceroute, dig, ss and packet capture with Wireshark or tcpdump, and how to read what they tell you.
44 min 1 quiz Graded labs: 3 - 7.Wireless, VPNs & Firewalls — Guarding the Edges
How Wi-Fi works and how to secure it (WPA2/WPA3), how a VPN builds an encrypted tunnel across an untrusted network, and how stateless and stateful firewalls decide which packets to allow. Includes NAT and the role of DMZs and network segmentation.
43 min 1 quiz Graded labs: 3
Securing the network
Common attacks, the defences that stop them and the principles behind them.
- 8.Network Security Basics — Attacks and the Defences That Stop Them
Common network attacks and the defences that stop them: spoofing, man-in-the-middle, denial of service, port scanning detection, and the principles of least privilege, segmentation and defence in depth. Builds the vocabulary you need before any security specialty.
43 min 1 quiz Graded labs: 3
Run a real example
This is the kind of code you will write. Run it, then change it and run it again.
PythonThe calculation every network engineer does by hand: one /26 holds 64 addresses, 62 of them usable. Change the prefix to /27 and predict the new range first.
Recommended challenges
Put the skills to work against a puzzle with a flag or a test suite.
Badges
Earned automatically from your progress on this device.
First Packet
LockedFinish your first lesson.
0 / 1
Subnet Surgeon
LockedPass 2 graded lab exercises.
0 / 2
Layer Cake
LockedComplete every foundations lesson.
0 / 4
Protocol Whisperer
LockedScore 80% or more on the first try in 4 lesson quizzes.
0 / 4
Network Engineer
LockedComplete every lesson in the track.
0 / 8
Certificate of completion
Lessons completed: 0 / 8
Complete every lesson to unlock your certificate.