Beyond Static Rule Checking Statistical inference to reduce manual pain. ("Beliefs") 100 routers, 99 have ACLs configured to deny prefix 192.168.0.0/16. All eBGP sessions to an AS but one have the same import/export policies. Capturing dynamic effects. ("Sandbox") Property violations that appear due to timing, message orderings, failures, etc. Avoiding low-level silliness. ("Synthesis") Configuration should be specified at the intent level, not at the mechanism level.