Policy and filtering modules transform the abstract into craft. Route-maps, prefix-lists, and community tagging become the artisan’s tools. Jeremy guides learners through step-by-step labs: crafting a policy that rejects bogons, carving precise advertisements to a provider, or tagging routes so downstream peers behave predictably. He doesn’t hide the messiness—misapplied filters can orphan prefixes—and highlights troubleshooting patterns that turn panic into methodical diagnosis.