Blog

BGP was designed when every AS was trusted. Accidental route leaks and deliberate prefix hijacks have caused repeated major outages. How to detect them, prevent them, and protect your AS from the blast radius when others make mistakes.

Default BGP convergence can take 3 minutes to notice a dead peer. That is fine on the public internet and unacceptable in enterprise or data center BGP. Every knob for reducing BGP failover time on Cisco IOS XE, including BFD.

You set local-pref, route maps, and communities, and traffic still goes the wrong way. BGP is deterministic; a surprise path means either policy is not applied where you think, or a higher priority step decided first.

The BGP session is Established but routes are missing. A missing prefix can be stopped at any of several pipeline stages, from injection to best path to output filtering. A methodical troubleshooting guide to BGP route advertisement.

A BGP session that will not reach Established is the most common BGP issue. The FSM state tells you exactly where the problem is; the root cause inside each state can be one of many things. A systematic IOS XE methodology.

Service provider BGP operates at a scale that dwarfs enterprise: full tables, hundreds of peers, thousands of routers. An SP BGP design guide covering peering relationships, policy, iBGP scaling, and transit economics.