problem of the Internet scalable configuration management higher layer connectivity requirements hard are to express, manage, maintain, verify still working, simulate, model today's routing configuration languages are based on low-level mechanism, rather than operator intent networks are configured at the element (or router) level, rather than as a single cohesive unit with well-defined policies and constraints key network operations goals require tweaking configs in pursuit of desired indirect effect on the network traffic engineering, security usual mode of coping: monitor for things that break not things that -might- break if you make a change use Internet as a simulator "`current best practices?' is that a band?" lots of things to configure, even along one path: router, switch, load balancer, (NAT) host, OS, web server, application, database. configuration management is everywhere word for the decade?: abstraction