An intemetwork system has several interlinked computer networks, each network having an associated element manager which is arranged to communicate with a router via a first network management protocol. Each element manager converts from the first network management protocol to a second protocol and also communicates via the network manager. The network manager allows a user of the system to control a router by issuing a command at the network manager and/or to view information on the status, configuration and/or performance of the router.