Sharing security intelligence is incredibly important to how Janet CSIRT works to secure the UK's national research and education network. Five years ago monitor our networks provided most of our incidents but today the majority of incidents are reported to us by a very small number of external partnerships. In this presentation I talk about some of the successful information sharing arrangements that Janet CSIRT has in place with other organizations, the best practices that use, and how good information sharing works in practice. I'll compare the more formal, structural and contractual approaches with informal, reputational, peer to peer networks that have built up within the industry. I'll also provide a brief overview of some data exchange formats, and how these compare to the data that we see in our day to day work.