Dell Brocade G620 Brocade 8.0.1 Fabric OS Command Reference - Page 834

portLoopbackTest portLoopbackTest Performs a functional test of port N->N path. Synopsis portloopbacktest [--slot slot] [-nframes count] [-lb_mode mode] [-spd_mode mode] [-ports itemlist] [-uports itemlist] Description Use this command to verify the functional operation of the switch by exercising the blade ports of the switch. This test sends frames from a given port's transmitter and loops them back into the same port's receiver. The loopback is done at the parallel loopback path. The path traversed in this test does not include the media or the fiber cable. Only one frame is transmitted and received at any given time. The port LED blinking pattern depends on the hardware platform on which the test is run. On 8 Gbps-capable platforms, the LEDs flicker green rapidly while the test is running. Only the ports on which the test is running flicker green. On 16 Gbps-capable platforms, the LEDs on all ports will flash amber, then turn to green, and then return to amber. After the test completes the lights turn to the expected switch disabled pattern. This difference in LED patterns is due to a difference in the ASIC design. Refer to the "Supported hardware and software" section in the Fabric OS Command Reference for a mapping of ASIC types to switch models. The test performs the following operations: 1. Sets all ports for parallel loopback. 2. Creates a frame F of maximum data size (2,112 bytes). 3. Transmits the frame F through port N. 4. Picks up the frame from the same port N. 5. Checks if any of the following eight statistic error counters report nonzero values: ENC_in, CRC_err, TruncFrm, FrmTooLong, BadEOF, Enc_out, BadOrdSet, DiscC3 6. Checks whether the transmit, receive, or class 3 receiver counters are stuck at some value. 7. Checks whether the number of frames transmitted is not equal to the number of frames received. 8. Repeats Steps two through seven for all ports until one of the following conditions is met: a. The number of frames (or pass count) requested is reached. b. All ports are marked bad. At each pass, the frame is created from a different data type of a palette of seven. If seven passes are requested, seven different data types are used in the test. If eight passes are requested, the first seven frames use unique data types, and the eighth is the same as the first. The seven data types are: 810 Brocade Fabric OS Command Reference 53-1004112-02