Data communication network

A data communication network having a number of end stations (A-E) connected together for data communication therebetween. At least one network interconnect device (B1-B6) receives and transmits data packets. The network interconnect device (B1-B6) further includes a memory (10) and a processor (9), each end station and network interconnect device being adapted to transmit data in accordance with a protocol in which copies of a route recording data packet are transmitted along multiple routes through the network. The memory (10) of the network interconnect device is adapted to store information relating to the manner in which route recording data packets reach the network interconnect device. The processor (9) compares the manner in which a currently received route recording data packet has reached the network interconnect device with information stored in the memory (10) corresponding to a previously received version of the route recording data packet and only forwards the currently received route recording data packet if the comparison indicates a predetermined condition is satisfied.