s5560镜像交换机，端口只有出方向流量没有进方向流量。这个算正常吗？

 Peak input rate: 0 bytes/sec, at 2013-02-14 06:04:52 

 Peak output rate: 122938861 bytes/sec, at 2013-11-03 01:49:12 

 Last 300 second input: 0 packets/sec 0 bytes/sec 0%

 Last 300 second output: 0 packets/sec 72 bytes/sec 0%

 Input (total):  0 packets, 0 bytes

         0 unicasts, 0 broadcasts, 0 multicasts, 0 pauses

 Input (normal):  0 packets, - bytes

         0 unicasts, 0 broadcasts, 0 multicasts, 0 pauses

 Input:  0 input errors, 0 runts, 0 giants, 0 throttles

         0 CRC, 0 frame, - overruns, 0 aborts

         - ignored, - parity errors

 Output (total): 42569876805380 packets, 17683170635431836 bytes

         42470177232380 unicasts, 24590256325 broadcasts, 75109316675 multicasts, 0 pauses

 Output (normal): 42569876805380 packets, - bytes

         42470177232380 unicasts, 24590256325 broadcasts, 75109316675 multicasts, 0 pauses

 Output: 0 output errors, - underruns, - buffer failures

         0 aborts, 0 deferred, 0 collisions, 0 late collisions

         0 lost carrier, - no carrier