SPRUJ17H March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The ALE supports OAM loopback on ports so that a remote link can be tested. TA port placed in OAM loopback will echo packets received on a port back to the port with an egress opcode of 0xFF which will swap the SA and DA on egress in the CPSW.
Any supervisory packet will not be affected, so the spanning tree and other bridging functions are not affected.
Packets will only be echoed if the port is in OAM loopback mode, the received packet in not a supervisor packet, the port is in a forwarding state, the packet received DA!=SA, and there are no errors in the packet.
When a port is in OAM loopback the port will not egress traffic from other ports, no address for loop backed traffic will be learned if enabled. Any packet received on the OAM loopback port with an error will be processed as if the port is not in OAM. That is if the host has enabled copy errored frames the errored frames will be sent to the host instead.