1. A non-transitory computer readable medium storing a computer program which, when executed by at least one processor in a network resource, identifies network resources on a computer network, the computer program comprising sets of instructions to cause the network resource to: send, from the network resource, a plurality of identifier requests to a plurality of other network resources requesting that the other network resources provide identifiers for a plurality of different protocols; receive one or more identifiers from each of the other network resources in response to the identifier requests, each identifier associated with a respective network resource for one of the protocols, wherein a first plurality of identifiers is received from a first network resource; use the first plurality of identifiers to identify the first network resource uniquely; and provide a single identifier of the one or more identifiers received from each of the other network resources in a list of network resources.