Displays the device counters kept for the link. The numbers displayed represent the values recorded since the last time the counters were reset (when the node first started or when the ZERO COUNTERS command was used). Do not use the /BRIEF or /FULL qualifier with this qualifier. Counters Common to CSMA/CD and FDDI Links lists and describes counters common to both CSMA/CD (carrier sense, multiple access with collision detect) and FDDI (fiber distributed data interface) links. Table 1 Counters Common to CSMA/CD and FDDI Links Counter Description Messages received The total number of messages received over the link. Multicast The total number of multicast messages messages received received over the link. Bytes received The total number of bytes of information received over the link. Multicast bytes The total number of multicast bytes received received over the link. System buffer The total number of times no system buffer was unavailable available for an incoming frame. Unrecognized The total number of times a frame was destination discarded because there was no portal with the protocol enabled. This count includes frames received for the physical address only. Messages sent The total number of messages sent over the link. Multicast The total number of multicast messages sent messages sent over the link. Bytes sent The total number of bytes of information sent over the link. Multicast bytes The total number of bytes of multicast sent messages sent over the link. User buffer The total number of times no user buffer was unavailable available for an incoming frame that passed all filtering. Data overrun The total number of bytes lost on the link's device because the local node's input buffers were full. A nonzero value can indicate noisy lines, a bad device, a busy or poorly tuned system (not enough resources allocated), or a hardware problem with another device on the LAN connection. Receive Errors Common to CSMA/CD and FDDI Links lists and describes receive errors common to both CSMA/CD and FDDI links. These errors, which are included in the display generated by the SHOW LINK/COUNTERS command, are represented by flags that indicate the error has occurred. Table 2 Receive Errors Common to CSMA/CD and FDDI Links Flag Description Block check error CRC error in packet(s) received. Framing error Received frame(s) ended incorrectly. Frame too long Frame(s) received longer than length limits. Frame status CRC error on ring noticed by local FDDI error station (FDDI only). Frame length Frame length too short (FDDI only). error Transmit Errors Common to CSMA/CD and FDDI Links lists and describes transmit errors common to both CSMA/CD and FDDI links. These errors, which are included in the display generated by the SHOW LINK/COUNTERS command, are represented by flags that indicate the error has occurred. Table 3 Transmit Errors Common to CSMA/CD and FDDI Links Flag Description Excessive Frame(s) failed to transmit because the collisions collision limit of 16 was reached (CSMA/CD only). Carrier check Indicates transceiver problem or short circuit failures in cable. Short circuit Short circuit in cable. Open circuit Open circuit in cable. Frame too long Frame(s) too long. Indicates a transmission problem in one of the portals using the link. Remote failure to A remote station failed to defer frame(s) defer transmission. Could indicate a misconfigured network. Transmit underrun Transmission of a frame was too slow. Indicates a hardware controller error. Transmit failure Frame(s) failed to transmit. CSMA/CD Counters lists and describes link counters specific to CSMA/CD only. Table 4 CSMA/CD Counters Counter Description Transmit CDC The total number of carrier detect check failure errors, that is, the number of times the local node failed to detect that another Ethernet station was already transmitting when the local node began transmitting. Messages Single collision-The total number of times transmitted: a frame was successfully transmitted on the second attempt after a normal collision on the first attempt. Multiple collision-The total number of times a frame was successfully transmitted on the third or later attempt after normal collisions on previous attempts. Initially deferred-The total number of times a frame transmission was deferred on its first attempt. This counter is used to measure Ethernet contention with no collisions. FDDI Counters lists and describes link counters specific to FDDI only. Table 5 FDDI Counters Counter Description Ring initializations The total number of times a ring initiated reinitialization was initiated by the link. Ring initializations The total number of times a ring received reinitialization was initiated by some other link. Directed beacons The number of times the link detected the received directed beacon process. Each invocation of the directed beacon process is counted only once. Connections completed The number of times the station successfully connected to the concentrator. Duplicate tokens The number of times a duplicate token was detected detected on the link. Ring purge errors The number of times the ring purger received a token while still in the ring purge state. LCT rejects Link Confidence Test rejects. Indicates a problem with communication between station and concentrator. Elasticity buffer Elasticity buffer function errors. errors Indicates a station on the ring with a transmit clock out of tolerance. MAC error count The number of times the MAC (Media Access Control) changed the E indicator in a frame from R to S. Traces initiated The number of times the PC-trace process was initiated by the link. Traces received The number of times the link was requested to perform the PC-trace process. Ring beacons The number of times the ring beacon initiated process was initiated by the link. Link errors The number of times the Link Error Monitor (LEM) detected an error in a received message. Slow counts are normal. Duplicate address The number of times the link address was a test failures duplicate. FCI strip errors The number of times a Frame Content Independent Strip operation was terminated by receipt of a token. LEM rejects The number of times excessive LEM errors were encountered. MAC frame count The total number of frames (other than tokens) seen by the link. MAC lost count The total number of times a frame (other than a token) was improperly terminated.