HP Brocade 8/24c Brocade Fabric OS Command Reference Manual Supporting Fabric - Page 736

22 portCmd bad CRC payloads rx Number of bad CRC payloads received. out of seq PDUs rx Number of out-of-sequence PDUs received. flow control count Flow control count. last rtt Last Round trip in milliseconds (RT traffic only). When issued with the ipperf option, this command determines characteristics of the path to the remote host. The output of the --ipperf -S command includes the following information: Sampling frequency(s) The interval specified with the -i option or the default (30 seconds). Total Time(s) The time in seconds the command has been running since it was last issued. BW The bandwidth measured in the last interval. Bandwidth is defined as the total number of transmitted packets in bytes. BW represents what the FCIP tunnel and the FC application register as throughput rather than the Ethernet on-the-wire bytes. WBW The current bandwidth weighted with a gain of 50%. Loss(%) The number of TCP retransmits. This number averages the TCP retransmit rate over the last display interval. Delay(ms) The smoothed TCP round-trip time and variance estimate in milliseconds. PMTU The path maximum transmission unit (MTU) represents the largest IP layer datagram that can be transmitted over the end-to-end path without fragmentation. This value is measured in bytes and includes the IP header and payload. There is limited support for black hole PMTU detection. PTMUs of decreasing size are sent: Jumbo PMTU (greater than 1500 bytes), 1500 bytes, and 1260 bytes, the minimum PMTU supported for FCIP tunnels. If the 1260 PMTU transmission fails, the --ipperf command terminates. There is no support for aging. During black hole PMTU detection the BW, WBW, Loss and PMTU values printed may not be accurate. VLAN tagging ensures that test traffic traverses the same path as real FCIP traffic. A VLAN tag entry must exist prior to issuing the --ping or --traceroute commands; this includes both the local and remote sides. A VLAN Tag table entry is dynamically maintained by the ipperf application. NOTES The -crc option to portCmd --tperf is no longer supported as of Fabric OS v7.0.0. End-to-end path characterization is not supported if an IPSec-enabled tunnel exists that uses the same source/local IP address. Make sure to use the --ping and --ipperf commands with a double-dash (--). If the dashes are omitted, a message displays indicating that the command is deprecated. The execution of this command is subject to Virtual Fabric or Admin Domain restrictions that may be in place. Refer to Chapter 1, "Using Fabric OS Commands" and Appendix A, "Command Availability" for details. 702 Fabric OS Command Reference 53-1001764-01