A firewall service for a cloud computing environment is described that uses an application identifier-based ruleset to process data packets. An application identifier-based rule may provide an action to be taken on a received packet based on the source application identifier, the destination application identifier, and/or an identification token associated with the source application. A firewall controller may verify applications of the computing environment, provide unique application identifiers, and manage the application identifier rules for one or more firewalls of the computing environments.