Code-Memo

Networking

1. Networking Fundamentals

  1. What a network is
  2. LAN vs WAN vs Internet
  3. Client-server model
  4. Packet switching vs circuit switching
  5. Bandwidth, latency, throughput, jitter

2. OSI Model

  1. OSI 7 layers overview
  2. Physical -> Application layer breakdown
  3. What happens at each layer in real systems
  4. Encapsulation & decapsulation
  5. Why OSI matters in debugging

3. TCP/IP Model

  1. TCP/IP vs OSI mapping
  2. TCP, UDP basics
  3. IP layer responsibilities
  4. Real-world internet communication flow

4. IP Addressing

  1. IPv4 structure and subnetting basics
  2. IPv6 overview
  3. Public vs private IPs
  4. Static vs dynamic IPs
  5. CIDR notation (/24, /16, etc.)

5. Subnetting & CIDR

  1. Why subnetting exists
  2. Network vs host bits
  3. Subnet masks explained
  4. VPC subnet design in cloud
  5. Practical subnet calculations

6. DNS (Domain Name System)

  1. How DNS works step-by-step
  2. A, AAAA, CNAME, MX records
  3. DNS resolution flow
  4. TTL and caching
  5. DNS in cloud (Route53 / equivalents conceptually)

7. HTTP / HTTPS

  1. HTTP request/response lifecycle
  2. Methods
  3. Status codes
  4. Headers and cookies
  5. HTTPS + TLS handshake basics

8. TLS / SSL

  1. Encryption basics
  2. Certificates and CAs
  3. TLS handshake flow
  4. Why HTTPS is secure
  5. Certificate management in cloud

9. Networking Protocols

  1. TCP vs UDP deep understanding
  2. ICMP
  3. SSH, FTP, SFTP
  4. WebSocket basics

10. Routing & Switching

  1. What routers and switches do
  2. MAC vs IP addressing
  3. ARP protocol
  4. Routing tables
  5. Default gateway concept

11. NAT (Network Address Translation)

  1. Why NAT exists
  2. Types: SNAT, DNAT, PAT
  3. NAT in home vs cloud networks
  4. NAT gateways in AWS-style architectures

12. Load Balancing

  1. What a load balancer does
  2. Layer 4 vs Layer 7 load balancing
  3. Round robin, least connections, etc.
  4. Health checks
  5. Sticky sessions

13. Firewalls & Security Groups

  1. Stateless vs stateful firewalls
  2. Inbound vs outbound rules
  3. Security groups vs NACLs (cloud concept)
  4. Port-based filtering
  5. Basic network security model

14. VPNs & Private Networking

  1. What VPNs do
  2. Site-to-site vs client VPN
  3. Tunnels
  4. Private connectivity in cloud

15. Cloud Networking

  1. VPC concept
  2. Subnets, route tables, gateways
  3. Internet Gateway vs NAT Gateway
  4. Peering networks
  5. Multi-region networking basics

16. Containers & Networking

  1. Docker networking basics
  2. Bridge, host, overlay networks
  3. Port mapping
  4. Kubernetes networking overview
  5. Service discovery in clusters

17. Kubernetes Networking

  1. Pod networking model
  2. Services
  3. Ingress controllers
  4. CNI plugins concept
  5. DNS inside Kubernetes

18. Observability & Network Debugging

  1. Ping, traceroute, nslookup tools
  2. netstat / ss basics
  3. curl for debugging HTTP
  4. Packet capture basics
  5. Common failure patterns

19. Performance & Scaling

  1. Latency vs throughput optimization
  2. CDN concept
  3. Edge networking
  4. Caching strategies
  5. Bottlenecks in distributed systems

20. Advanced Networking Concepts

  1. BGP
  2. Anycast vs unicast vs multicast
  3. Zero Trust networking
  4. Service mesh
  5. SDN (Software Defined Networking)