aluExtPortEtherLoopback is used to put an ethernet port into a loopback mode. Setting aluExtPortEtherLoopback must be accompanied by setting aluExtPortEtherLoopbackTimer for the same port. A 'line' loopback loops frames received on this port back to the remote system. An 'internal' loopback loops frames from the local system back at the framer. Use 'none' to turn off either one of the above loopback mode. The Nokia 7705 SAR devices restrict the following interactions: - A 'line' loopback is only allowed on ports with aluExtPortEtherLoopbackCfmLbMode set to 'disabled'. - An 'internal' loopback is only allowed on ports with tmnxPortMode set to 'access (1)'. - aluExtPortEtherLoopback can only be 'none' if dot3OamAdminState of the port is 'enable (2)'. - aluExtPortEtherLoopback can only be 'none' if aluExtPortEtherLoopbackCfmLbMode of the port is not 'disabled (0)'.