NETWORK TOPOLOGY

A method of determining the topology of at least part of a network comprising the steps of: monitoring traffic to and/or from a plurality of computers in the network; storing information relating to the monitored traffic for each of the plurality of computers, the information including an identifier of a requested service; selecting a first computer of the plurality of computers; reading the stored information related to the first computer and identifying, using the stored identifier of the requested service, at least one traffic flow to or from the first computer that corresponds to the requested service; using the stored information to identify the destination or origin of the identified traffic flow for the first computer, which traffic flow information includes the identifier of the requested service; using the identified destination or origin to identify one or more computers that are immediately upstream or downstream of the first computer, and determining a topology based on the identified one or more upstream or downstream computers.