Stacking | 217Figure 17-27. show hardware stack-unit stack-port Command ExampleFailure ScenariosThe following sections describe some of the common fault conditions that can happen in a switch stack andhow they are resolved.Stack Member FailsProblem: A unit that is not the stack master fails in an operational stack.Resolution: If a stack member fails in a daisy chain topology, a split stack occurs. If a member unit fails ina ring topology, traffic is re-routed over existing stack links.The following syslog messages are generated when a member unit fails:FTOS#May 31 01:46:17: %STKUNIT3-M:CP %IPC-2-STATUS: target stack unit 4 not respondingMay 31 01:46:17: %STKUNIT3-M:CP %CHMGR-2-STACKUNIT_DOWN: Major alarm: Stack unit 4 down - IPCtimeoutFTOS#May 31 01:46:17: %STKUNIT3-M:CP %IFMGR-1-DEL_PORT: Removed port: Te 4/1-32,41-48, Fo 4/49,53FTOS#May 31 01:46:18: %STKUNIT5-S:CP %IFMGR-1-DEL_PORT: Removed port: Te 4/1-32,41-48, Fo 4/49,53Unplugged Stacking CableProblem: A stacking cable is unplugged from a member switch. The stack loses half of its bandwidth fromthe disconnected switch.Resolution: Intra-stack traffic is re-routed on a another link using the redundant stacking port on theswitch. A recalculation of control plane and data plane connections is performed.FTOS# show hardware stack-unit 1 stack-port 33Input Statistics:7934 packets, 1049269 bytes0 64-byte pkts, 7793 over 64-byte pkts, 100 over 127-byte pkts0 over 255-byte pkts, 7 over 511-byte pkts, 34 over 1023-byte pkts70 Multicasts, 0 Broadcasts0 runts, 0 giants, 0 throttles0 CRC, 0 overrun, 0 discardedOutput Statistics:438 packets, 270449 bytes, 0 underruns0 64-byte pkts, 57 over 64-byte pkts, 181 over 127-byte pkts54 over 255-byte pkts, 0 over 511-byte pkts, 146 over 1023-byte pkts72 Multicasts, 0 Broadcasts, 221 Unicasts0 throttles, 0 discarded, 0 collisions, 0 wredDropsRate info (interval 45 seconds):Input 00.00 Mbits/sec, 0 packets/sec, 0.00% of line-rateOutput 00.00 Mbits/sec, 0 packets/sec, 0.00% of line-rate
