Advanced Networking Concepts
BGP
- Border Gateway Protocol: the Internet’s routing protocol between autonomous systems (ASes).
- Enables route advertisement, policy-based routing, and multi-homing.
- Key idea: routing is driven by policy and path attributes, not just shortest path.
Anycast vs unicast vs multicast
- Unicast: one sender → one receiver (typical client-server).
- Multicast: one sender → many receivers in a group (specialized networking).
- Anycast: one IP advertised from many locations; traffic goes to a “nearest” location by routing policy (common in DNS/CDNs).
Zero Trust networking
- “Never trust, always verify”: authenticate/authorize every request regardless of network location.
- Common building blocks: identity-aware proxies, mTLS, short-lived credentials, continuous evaluation.
Service mesh
- Infrastructure layer for service-to-service communication (mTLS, retries, timeouts, observability).
- Implemented via sidecars or ambient models; adds control but also operational complexity.
SDN (Software Defined Networking)
- Separates control plane from data plane; network behavior is programmable.
- Enables centralized policy, automation, and dynamic traffic engineering in data centers/cloud.