Agenda
1，常用线缆及收发器
2，交换机端口类型
3，常用命令
4，常用诊断工具
5，光口不能UP故障
6，电口为半双工故障
7，端口UP/DOWN故障
8，端口err-disable故障
9，网络排障方法总结
10，Console Port介绍
11，Lenovo TOR 交换机家族**
The OSI Reference Model
常用线缆及收发器
Small Form Pluggable (SFP)
● 1 Gbps速率
● Copper TX or Fiber
★ 1个光纤通道
★ Lucent Connector (LC)
Small Form Pluggable Plus (SFP+)
● 10 Gbps or 1 Gbps速率
● Same size as SFP
● DAC or Fiber
★ 1个光纤通道
★ Lucent Connector (LC)
Quad Small Form Pluggable (QSFP)
● 40 Gbps速率
● 4 x 10 Gbps lanes
★ Runs in 40 Gbps or
★ 4 x 10 Gbps
● DAC or Fiber
★ 4个光纤通道
★ MTP 和MPO连接器
Quad Small Form Pluggable 28 (QSFP28)
● 100 Gbps速率
● Same size as SFP
● 4 x 28 Gbps lanes
★ Runs in 100 Gbps or
★ 4 x 25 Gbps
● DAC or Fiber
★ 4个光纤通道
Small Form Pluggable 28 (SFP28)
● 25 Gbps速率
● 1 x 28 Gbps lanes
● Same size as SFP
● DAC or Fiber
★ 1个光纤通道
SFP+ Direct Attach Cable
● For SFP+ port 10GbE connectivity over short distances (7m and less).
● NO OPTICS REQUIRED.
● Lengths: 0.5m, 1m, 3m, 5m, 7m
● SFP+ DACs cannot negotiate to 1GbE. 10GbE only.
● SFP+ DACs are all PASSIVE
SFP+ Active Optical Cable
● For SFP+ port 10GbE connectivity over longer distances or for cable management.
● NO OPTICS REQUIRED.
● Lengths: 2m, 3m, 5m, 7m, 10m, 15m, 20m
● Cannot negotiate to 1GbE. 10GbE only.
● Active Optical Cables draw more power than passive
QSFP+ Direct Attach Cable
● For QSFP+ port 40GbE connectivity over short distances (7m and less).
● NO OPTICS REQUIRED.
● Lengths: .5m, 1m, 2m, 3m, 5m, 7m
● Mainly used for 40GbE mode on a QSFP+ port, it can also be used for
4x SFP+ breakout mode if both QSFP+ ports on either end are set to
“breakout mode.”
● QSFP+ Copper DACs are all PASSIVE
QSFP+ Active Fiber Direct Attach Cables
● For QSFP+ port 40GbE connectivity over longer distances than QSFP+ copper
DACs, without having to pay for optics.
● Lengths: 10m, 50m
● Mainly used for 40GbE mode on a QSFP+ port, it can also be used for 4x SFP+
breakout mode if both QSFP+ ports on either end are set to “breakout mode.”
QSFP+ to 4x SFP+ Breakout Direct Attach Cable
● For QSFP+ port breakout into 4x SFP+ ports over short distances (7m and less)
● Lengths: .5m, 1m, 2m, 3m, 5m, 7m
● When breakout mode was enabled on the QSFP+ port, sees 4x 10GbE ports as separate
port numbers in switch
● QSFP+ Copper DACs are all PASSIVE
QSFP+ to 4x RJ45 1GB Breakout DAC
● breakout 40GB QSFP+ port into (4) 100/1000baseT RJ45 connections which will
accept Cat5/6 patch cables
● Up to 100m on CAT5e twisted pair cable
● Connectors: (1) QSFP+ and (4) RJ45 (female, plug in M/M patch cables)
MTP to 4x LC Breakout Fiber Cable
● For QSFP+ Optic breakout into 4x LC connections.
● Requires SFP+ Optics on the LC ends.
● Overall Lengths: 1m, 3m, 5m, 7m
● OM4 MTP to 4x LC Fiber
MTP to 4x LC SMF Breakout Fiber Cable
● use with QSFP+ PSM4-LR Optic SMF breakout into 4x LC connections.
● Requires LR SFP+ Optics on the 10Gb ends.
● Single Mode Fiber MTP to 4x LC connectors
● Up to 10k over 9/125 Single Mode Fiber when plugged into female patch panel port
100G QSFP28 to 2x50G QSFP28 Passive Direct Attach Copper Breakout Cable
● Connector Type: QSFP28 to 2 QSFP28
● Max Data Rate: 100Gbps
● Cable Type: Passive Copper Cable
● Wire AWG: 28AWG/30AWG
● Temperature: 0 to 70°C (32 to 158°F)
直接连接电缆(DAC)
DAC = Direct Attach Cable, 叫做直连电缆或直连铜缆，简单来说就是一根线缆的两端自带有收发器模
块。可以与交换机、服务器、路由器、网络工作接口卡（NICs）和主机总线适配器（HBAs）连接，为网路
传输提供高密度、高数据的处理功能
有源光缆（AOC）
AOC = Active Optical Cable, 有源光缆由多模光纤、光收发器件、控制芯片和并行光模块组成。有源
光缆两端的光收发器提供光电转换以及光传输功能，以提高光缆的传输速度和传输距离，而不会减弱与标准
电接口之间的兼容性
光纤线主要分为两类：
● 单模光纤(Single-mode Fiber)：一般光纤跳线用黄色表示，接头和保护套为蓝色；传输距离较长。
● 多模光纤(Multi-mode Fiber)：一般光纤跳线用橙色表示，也有的用灰色表示，接头和保护套用米色
或者黑色；传输距离较短。
光纤使用注意事项！
光纤跳线两端的光模块的收发波长必须一致，也就是说光纤的两端必须是相同波长的光模块，简单的区分方
法是光模块的颜色要一致。 一般的情况下，短波光模块使用多模光纤（橙色 的光纤），长波光模块使用
单模光纤（黄色光纤），以保证数据传输的准确性。 光纤在使用中不要过度弯曲和绕环，这样会增加光在
传输过程的衰减。 光纤跳线使用后一定要用保护套将光纤接头保护起来，灰尘和油污会损害光纤的耦合。
光纤模块波长
● 短波（SX）:850纳米波长/550米
● 长波（LX）1310纳米波长/10公里
● 超长波（ZX）80公里距离
● SR代表短距离（short range），适配短波（波长为850nm）多模光纤（MMF）
● LR指的是长距离（Long Range），适配长波（1310nm）单模光纤（SMF）
短波配多模， 长波配单模!!!
● 短波光纤模块： 发光口大，传输距离近
● 长波和超长波光纤模块：发光口小，传输距离远
● 多模光纤：纤芯直径大，传输距离近
● 单模光纤：纤芯直径小，传输距离远
● 短波模块-单模光纤-短波模块：不可行！因为短波模块的发光口大于单模光纤的纤芯直径，部分光信号
无法进入光纤
● 长波模块-多模光纤-长波模块：一般可行，因为长波模块的发光口小于多模光纤的纤芯直径，所有光信
号能够进入光纤。但传输距离受多模光纤限制，只有几百米，而且可能会出现连通性不稳定甚至连不通
的情况！ 不是最佳实践！
● 长波模块-多模光纤-短波模块：不可行！两端波长必须相同！ 如果传输距离较远，必须选择 长波
模块-单模光纤-长波模块！
“OM” stand for optical multi-mode，即光模式，是多模光纤表示光纤等级的标准。不同等级传输时的
带宽和最大距离不同，从以下几个方面分析它们之间的区别
