Roadmap › 0. Fundamentals › Step 4
NET
Networking & Hosting — How a Website Works, End to End
The complete life cycle of a web request — OSI and TCP/IP models, IP addresses, subnets and ports, DNS, TCP vs UDP, TLS/HTTPS, HTTP/1.1, HTTP/2 and HTTP/3, browser rendering, cookies and sessions, proxies, load balancers and CDNs, web servers (IIS, Kestrel, Nginx), hosting options from shared hosting to cloud and containers, domains and SSL certificates, deploying an ASP.NET site to IIS and Azure, and troubleshooting network problems.
Quick revision for interview day. Print it or save it as a PDF.
Request life cycle
URL → cache/HSTS → DNS → TCP (or QUIC) → TLS → HTTP request → CDN/WAF → load balancer → web server → app → DB → response → DOM/CSSOM → layout → paint.
Layers
L7 HTTP/DNS · L4 TCP/UDP (ports) · L3 IP (routers) · L2 Ethernet/Wi-Fi (switches, MAC) · L1 physical. L4 vs L7 load balancing.
Numbers to know
Ports 80/443/22/3389/1433/6379/53 · private ranges 10/8, 172.16/12, 192.168/16 · /24 = 256 addresses · TLS 1.3 = 1 RTT · TTL 300 s before migrations.
Hosting choices
Shared → VPS/VM (IaaS) → PaaS (App Service) → containers (Container Apps/AKS) → serverless (Functions); static SPA → Static Web Apps/CDN.
Troubleshooting toolkit
nslookup/dig · ping/tracert · Test-NetConnection -Port · curl -v · DevTools Network timing · SSL Labs · IIS stdout log + Event Viewer · App Insights.