Networking

A practical guide to DNS covering record types, resolution flow, caching, and common tools for troubleshooting.

Production-level networking — BGP, anycast, container networking, mTLS, eBPF, service meshes, and network observability.

Deeper networking concepts mapped to OSI layers — packet captures, TCP internals, MTU issues, NAT, firewalls, and L4 vs L7 load balancing.

A practical breakdown of the 7 OSI layers, what happens at each one, the protocols involved, and how to troubleshoot at each level.