The browser reaches application code only after domain resolution, secure connection setup, and a selected HTTP transport. This track follows a permit portal through a DNS move, certificate rotation, HTTP/3 fallback, and a replay-sensitive approval. It separates control-plane changes from what a real client can still reach and what the origin has actually committed.
Topics in this track
- DNS TTL, Negative Cache, and Cutover Planning — Plan domain changes around cached positive and negative answers, not a single control-plane update.
- TLS Certificate Rotation and HSTS Scope — Renew certificates before expiry and apply HTTPS-only policy only across hosts that can sustain it.
- HTTP/2, HTTP/3 Negotiation, and Fallback Testing — Measure protocol choice and graceful fallback across browsers, proxies, and blocked network paths.
- Early Data Replay and Safe Request Admission — Keep state-changing requests out of replayable early data and bind retries to idempotent operations.
Prerequisite paths
First connection: separate name resolution, TLS, and HTTP; HTTP Delivery and Cache Ownership; Multi-Region Web State and Recovery.
Practice and check
Build Project: permit domain cutover and transport recovery and review Web Development: network transport operations quiz.