Wavelength of DWDM Optical Modules

https://support.huawei.com/enterprise/en/doc/EDOC1100074722/ceb1ac3c/configuring-the-channel-number-for-the-center-wavelength-of-dwdm-optical-modules

What Is A-FEC?

https://info.support.huawei.com/info-finder/encyclopedia/en/Adaptive+Forward+Error+Correction.html

DWDM linear network DWDM OLP network

3db attenuator

In some cases, the signal strength of the incoming signal may be too strong for the receiving device if the distance between the two devices is too short. Using an attenuator can help reduce the signal strength to a more appropriate level.

The hold up time and hold down time can be used to prevent routing loops and to improve the stability of the network. For example, if a router has a hold up time of 10 seconds and a hold down time of 20 seconds, and it declares a neighbor down, it will wait 10 seconds for a hello packet from the neighbor before declaring the neighbor down. If the router does not receive a hello packet from the neighbor within 10 seconds, it will wait 20 seconds before trying to re-establish the neighbor adjacency. This helps to prevent routing loops from occurring if the neighbor is only temporarily unavailable.

The hold up time and hold down time can also be used to improve the stability of the network by preventing flapping. Flapping occurs when a routing loop is created and then broken, and then created again. This can happen if a router is constantly declaring neighbors down and then up again. The hold up time and hold down time can help to prevent flapping by preventing a router from declaring a neighbor down too quickly.

—————spanning ——————-

show running-config | i spann no spanning-tree vlan 1565,1933,2389,2463,3029,3442,3826 DHUTRCLSW-01# show running-config | i spa no spanning-tree vlan 1565,1933,2389,2463,3029,3442,3826

HUTRCLSW-01(config)# no spanning-tree vlan 1467,1565,1933,2389,2463,3029,3442,3826

—————————————-Cisco Nexus L2 Switch port-channel configure —switchport–

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