ShelfDevOps / Platform EngineerCloud and Network EngineerCybersecurity Engineer
Networking fundamentals · Beginner · 8 h
IP, DNS, TCP and TLS
CIDR notation and subnet planning, how names resolve, what a TCP connection and a TLS handshake are, and how to diagnose each from the command line.
Why employers care: Most connectivity incidents are DNS, routing, firewall or certificate problems. Engineers who can tell them apart quickly save hours.
In the roadmaps for: DevOps / Platform Engineer, Cloud and Network Engineer, Cybersecurity Engineer
Lessons, in order
- IP addresses, CIDR and subnet planningRead CIDR notation, plan subnets for a cloud network across tiers and zones, and catch an overlap with the office network before it becomes an outage.3 min
- DNS, TCP and TLS from the command lineRun a local HTTPS server, resolve its name, and read the errors curl and openssl give for untrusted certificates, wrong names and closed ports.4 min