Here’s a structured, complete roadmap of what you need to learn in Networking, grouped by category (in English). Use it like a checklist: learn top → down, and keep looping back with labs.
1) Foundations (How networks “work”)
- What a network is: hosts, clients/servers, LAN/WAN, Internet vs intranet
- Network models:
- OSI model (Layer 1–7): purpose of each layer, what breaks where
- TCP/IP model: how it maps to OSI
- Encapsulation/decapsulation: frames → packets → segments
- Core concepts: bandwidth vs throughput, latency, jitter, loss, MTU, MSS
- Duplex & contention: half/full duplex, collisions (historical Ethernet)
2) Physical & Data Link Layer (L1/L2)
Physical (Layer 1)
- Media: copper (UTP/STP), fiber (SMF/MMF), wireless basics
- Connectors & standards: RJ45, SFP/SFP+, Ethernet speeds (1G/10G/25G/40G/100G)
- Signal basics: attenuation, interference, cable categories
- Topology: star, mesh, spine-leaf (data center concept)
Data Link (Layer 2)
- Ethernet framing: MAC addresses, unicast/multicast/broadcast
- Switching basics: CAM/MAC table learning, flooding, aging
- VLANs (802.1Q): access vs trunk ports, native VLAN concept
- STP/RSTP: loops, root bridge, port roles/states, why STP exists
- Link aggregation: LACP, why bundle links
- Wi‑Fi (802.11) basics: channels, 2.4/5/6 GHz, roaming, SSID, security modes
3) IP & Subnetting (Layer 3 fundamentals)
- IPv4 addressing: private vs public, CIDR notation
- Subnetting (critical):
- network ID, broadcast, usable range
- VLSM, summarization
- IPv6 basics:
- address types (global unicast, link-local, multicast)
- SLAAC vs DHCPv6 (high-level)
- ARP / Neighbor Discovery: how IP maps to L2 (IPv4 vs IPv6)
4) Routing (Layer 3 advanced)
- Routing concepts: routing table, longest prefix match, default route
- Static routing: when to use it
- Dynamic routing protocols:
- OSPF (common in enterprises)
- BGP (Internet / large networks; essential if you go deep)
- (Know what RIP/EIGRP are historically/optionally)
- Route redistribution (advanced): connecting different protocols
- Policy-based routing (PBR): route based on rules rather than table
5) Transport Layer (TCP/UDP) + Reliability
- TCP vs UDP: use cases, overhead, reliability
- TCP mechanics: 3-way handshake, seq/ack, windows, retransmissions
- Flow & congestion control: why throughput collapses sometimes
- Ports & sockets: how services are identified
6) Application Layer Protocols (What you actually use)
- DNS: records (A/AAAA/CNAME/MX/TXT), recursion vs authoritative, caching
- DHCP: DORA process, scopes, options, reservations
- HTTP/HTTPS: TLS basics, certificates, SNI, proxies
- Email: SMTP/IMAP/POP3 basics
- File transfer: SFTP vs FTP
- NTP: time sync importance
- SSH: remote management fundamentals
- SNMP: monitoring basics (v2c vs v3 conceptually)
7) Network Services & Network Design (Real-world building blocks)
- NAT/PAT: why it exists, port translation, typical home/enterprise patterns
- Load balancing (intro): L4 vs L7, health checks
- Proxy & reverse proxy: when/why
- QoS: marking, shaping vs policing, priority queues (voice/video)
- High availability: redundancy, failover, HSRP/VRRP concepts
- Address planning: IP plan, VLAN plan, summarization strategy
8) Security Fundamentals (Networking-focused)
- CIA triad & threat basics
- Firewalls: stateless vs stateful, zones, rules, default-deny mindset
- ACLs: L3/L4 filtering logic
- VPNs:
- site-to-site vs remote access
- IPsec basics, SSL VPN concept
- Network segmentation: VLANs, subnets, micro-segmentation concept
- 802.1X / NAC basics: controlling access to the network
- Wireless security: WPA2/WPA3, enterprise vs personal
- Common attacks to recognize: spoofing, ARP poisoning, MITM, DDoS (high-level)
9) Operations: Troubleshooting & Tooling (Must-have)
- Troubleshooting methodology: isolate layer by layer
- CLI tools (Windows/Linux):
- `ping`, `traceroute/tracert`, `ipconfig/ifconfig`, `netstat/ss`
- `nslookup/dig`, `arp`, `route`, `curl`
- Packet analysis: Wireshark basics (filters, TCP handshake, DNS flows)
- Logs & telemetry: syslog concepts, event correlation
- Performance testing: iPerf basics, latency checks
10) Automation & Programmability (Modern networking)
- Scripting: Python basics for networking tasks
- APIs & formats: REST, JSON, YAML
- Automation tools (conceptual): Ansible-style configuration automation
- Network data models (advanced): NETCONF/RESTCONF, YANG (optional)
- Version control: Git basics for config/automation
11) Cloud & Virtual Networking (Very important today)
- VPC/VNet concepts: subnets, route tables, security groups/NACLs
- Internet gateways/NAT gateways
- Hybrid connectivity: VPN to cloud, direct connect concepts
- Containers & networking basics: service discovery, ingress (high-level)
12) Specialized Tracks (Pick based on goals)
- Enterprise networking: campus LAN, wireless, NAC, SD-WAN
- Data center networking: spine-leaf, EVPN/VXLAN (advanced)
- Service provider/Internet: BGP deep dive, traffic engineering
- Security engineering: IDS/IPS, SIEM, zero trust architecture
- Network reliability/SRE: monitoring, incident response, capacity planning
Recommended learning order (practical sequence)
- OSI + TCP/IP + basic tools
- Ethernet switching + VLAN + STP
- IPv4 + subnetting (daily practice)
- Routing (static → OSPF → BGP basics)
- DNS/DHCP/HTTP/TLS
- NAT + firewall/ACL + VPN
- Wireshark + troubleshooting
- Cloud networking + automation
Quick questions (so I can tailor the roadmap)
- What’s your goal: IT support / network engineer / cybersecurity / cloud?
- Do you want a certification path (e.g., CCNA-level, Network+ level), or purely practical?
- Are you starting from zero, or do you already know IP/subnetting?
If you answer these, I can turn the categories above into a week-by-week study plan with labs and checkpoints.