一次上架锐捷交换机，由于ODF光衰不稳定，导致交换机端口down，排查很多发现以下故障：
重置18010-X端口发现提示一下命令：
Port in violation! Use 'errdisable recovery' command to up the port!
gz-sprine1#show interfaces tenGigabitEthernet 4/5 status
Interface Status Vlan Duplex Speed Type
---------------------------------------- -------- ---- ------- --------- ------
TenGigabitEthernet 4/5 disabled routed Unknown Unknown fiber
修改 err为30s: errdisable recovery interval 30
恢复出错的端口：errdisable recovery cause link-state
重新检查交换机的状态，恢复正常。
gz-sprine1#show interfaces tenGigabitEthernet 4/5 st
gz-sprine1#show interfaces tenGigabitEthernet 4/5 status
Interface Status Vlan Duplex Speed Type
---------------------------------------- -------- ---- ------- --------- ------
TenGigabitEthernet 4/5 down routed Unknown Unknown fiber
gz-sprine1#
备注：端口处于error状态，端口不会发光，技术上称为假死。