HP StorageWorks 2/64 HP StorageWorks Fabric OS 5.x Command Reference Guide (AA - Page 500

portLoopbackTest Functional test of port N->N path. Synopsis portloopbacktest [--slot number][-nframes count][-lb_mode mode] [-spd_mode mode][-ports itemlist] Availability admin Description Use this command to verify the functional operation of the switch by sending frames from the port N transmitter and looping them back into the same port N receiver. The loopback is done at the parallel loopback path. The path exercised in this test does not include the media or the fiber cable. Only one frame is transmitted and received at a time. No external cable is required to run this test. The port LEDs flicker green rapidly while the test is running. Following is the test method: 1. Set all ports for parallel loopback. 2. Create a frame F of maximum data size (2,112 bytes). 3. Transmit frame F through port N. 4. Pick up the frame from the same port N. 5. Check the eight statistic error counters for nonzero values: ENC_in, CRC_err, TruncFrm, FrmTooLong, BadEOF, Enc_out, BadOrdSet, DiscC3 6. Check if the transmit, receive, or class 3 receiver counters are stuck at some value. 7. Check if the number of frames transmitted is not equal to the number of frames received. 8. Repeat step 2 through step 7 for all ports present until: - The number of frames (or passcount) requested is reached. - All ports are marked bad. At each pass, the frame is created from a different data type. 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: 1) CSPAT: 0x7e, 0x7e, 0x7e, 0x7e, ... 2) BYTE_LFSR: 0x69, 0x01, 0x02, 0x05, ... 3) CHALF_SQ: 0x4a, 0x4a, 0x4a, 0x4a, ... 4) QUAD_NOT: 0x00, 0xff, 0x00, 0xff, ... 5) CQTR_SQ: 0x78, 0x78, 0x78, 0x78, ... 6) CRPAT: 0xbc, 0xbc, 0x23, 0x47, ... 7) RANDOM: 0x25, 0x7f, 0x6e, 0x9a, ... Because this test does not include the media or the fiber cable in its test path, its results combined with the results of crossPortTest and spinSilk (both of which loop frames using an external loopback cable) can be used to determine which components of the switch are faulty. 500 Fabric OS commands