You can perform 3com 5500 (Netstream) configuration using the following steps:
ip netstream export source interface {LOOPBACK_INTERFACE_NAME}
ip netstream export host {NETFLOW_SERVER_IP} {NETFLOW_SERVER_LISTENER_PORT}
Enter global configuration mode on the router or MSFC, and issue the following commands for each interface on which you want to enable flow:
interface {INTERFACE_NAME}
ip netstream inbound