Communication apparatus includes a plurality of ports, including at least a first port configured to transmit and receive first data packets over a network in accordance with a network-layer protocol to and from a network management station, and a second port configured to be connected to a neighboring unmanaged device so as to transmit and receive second data packets to and from the unmanaged device in accordance with a link-layer protocol. A processor is configured to receive telemetry data from the unmanaged device via the second port in accordance with the link-layer protocol, to aggregate the received telemetry data in a memory, and to report the aggregated telemetry data to the network management station via the first port in accordance with the network-layer protocol.