rmon is a system defined by the ietf (internet engineering task force) hat allows you to monitor the traffic of lans or vlans.

    rmon is an integrated part of the switch software agent and continually collects statistics about a lan segment or vlan, and transfers the information to a management workstation on request or when a pre-defined threshold is crossed. the workstation does not have to be on the same network as the switch and can manage the switch by in-band or out-of-band connections.