Ethernet loopback
The Ethernet loopback functionality provides a means to gauge the network continuity
and performance of an Ethernet port.
The testing of network continuity is achieved by enabling the remote Ethernet device to swap the source MAC address with the destination MAC address and send the incoming frames back to the source. The looping of the incoming traffic back to the source allows to verify the maximum rate of frame transmission without any frame loss.
By enabling Ethernet loopback on multiple remote devices, the network performance of an entire Metro Ethernet Network (MEN) can be analyzed using a single traffic generator device installed at the network core. However, the loopback support is limited to a LAN segment.