今天领导安排,去楼层查看下cisco 3550设备光口是什么类型,到了楼层用show int g0/1把信息拷贝回来,仔细阅读后发现红色标记的地方正式光纤的类型.在网上查询后得知SX是多摸光纤传输<10公里．LX和LH是单摸光纤,LX传输距离进<25公里,LH传输距离远<70公里.也不知道自己理解是否正确,希望大家给予指正. 

Hardware is Gigabit Ethernet, address is 0007.8549.d0d9 (bia 0007.8549.d0d9)
  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive not set
  Auto-duplex (Full), 1000Mb/s, media type is LX
  output flow-control is off, input flow-control is off
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:03, output hang never
  Last clearing of "show interface" counters never
  Queueing strategy: fifo
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  5 minute input rate 2527000 bits/sec, 533 packets/sec
  5 minute output rate 2652000 bits/sec, 505 packets/sec
     38040353 packets input, 3467203172 bytes, 0 no buffer
     Received 2032203 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 1331313 multicast, 0 pause input
     639397853 packets output, 1844415782 bytes, 0 underruns
     0 output errors, 0 collisions, 4 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

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