You've learned how BGP enables routing across the internet's + autonomous systems.
Core concepts:
- IGPs route inside organizations. BGP routes between them.
- Autonomous Systems are independent routing domains with unique ASNs.
- AS_PATH prevents loops and influences decisions.
BGP mechanics:
- eBGP connects different ASes. iBGP distributes routes within an AS.
- Path attributes (LOCAL_PREF, AS_PATH, MED) control route selection.
Operations:
- Route filtering protects your network.
- Communities tag routes for signaling.
- Multihoming provides redundancy.
Security:
- RPKI validates route origins.