Peacekeeping is a noble and essential activity, helping to bring peace to conflict torn areas and providing security to millions of people around the world. Peacekeepers operate in all domains of war: buffer zones on land, no fly zones in the air and ensuring free passage at sea. With the emergence of cyberspace as a domain of war, questions on the role of peacekeeping in this domain naturally arise. There is extensive research around the topic of cyber warfare, but surprisingly little on how to restore and maintain peace in its aftermath. This is a significant gap which needs addressing. We begin by providing an overview of peacekeeping, describing its overarching goals and principles, using the United Nations model as a reference. We then review existing literature on cyber peacekeeping. The paper progresses to discuss the question of whether cyber peacekeeping is needed, and if so, if it is a plausible concept. We explore some ideas on how cyber peacekeeping could be performed and the challenges cyber peacekeepers will face, before making suggestions on where future work should be focused.