故障现象：Juniper QFX5100-24Q通过监控发现et-0/0/2上出现Error包。


通过命令：show interfaces et-0/0/2 extensive,显示input error以及CRC错误。


状态显示：


Physical interface: et-0/0/2, Enabled, Physical link is Up

  Interface index: 942, SNMP ifIndex: 516, Generation: 676

  Link-level type: Ethernet, MTU: 1514, Speed: 40Gbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled, Media type: Fiber

  Device flags   : Present Running

  Interface flags: SNMP-Traps Internal: 0x4000

  Link flags     : None

  Input errors:

    Errors: 771731, Drops: 0, Framing errors: 771415, Runts: 0, Policed discards: 0, L3 incompletes: 0, L2 channel errors: 0, L2 mismatch timeouts: 0, FIFO errors: 0, Resource errors: 0

  Output errors:

    Carrier transitions: 3, Errors: 0, Drops: 0, Collisions: 0, Aged packets: 0, FIFO errors: 0, HS link CRC errors: 0, MTU errors: 0, Resource errors: 0

…………………………

  MAC statistics:                      Receive         Transmit

    Total octets                 1216533781969    1073277356863

    Total packets                   1669078594       1462519491

    Unicast packets                 1633851744       1398747806

    Broadcast packets                   361455         27733729

    Multicast packets                 34865395         36037956

    CRC/Align errors                    771415                0

    FIFO errors                              0                0


初步排查，影响的原因有可能是以下几点： 

1. 接口模块 

2. 光线或网线

3. 两边接口是否全双工


解决办法：

经换模块，CRC显示正常，input error恢复正常。 开Case，对模块进行RMA处理。