Disclosed herein are systems, methods, computer media, and apparatuses for providing service chains. A control and monitoring system orders a service chain - an order of data flow through a plurality of network nodes - based on network node identifiers. The control and monitoring system provides a policy to all networking nodes in order to enforce the order of the service chain. In some embodiments, features are implemented to improve the availability of service chains. Such features include load-balancing, fail-over, traffic engineering, and automated deployment of virtualized network functions at various stages of a service chain, among others.