Operation Manual – DLDPH3C S3100 Series Ethernet Switches Chapter 1 DLDP Configuration1-1Chapter 1 DLDP ConfigurationNote:Only S3100-EI Series switches support DLDP feature.1.1 Overview1.1.1 IntroductionYou may have encountered unidirectional links in networking. When a unidirectionallink occurs, the local device can receive packets from the peer device through the linklayer, but the peer device cannot receive packets from the local device. Unidirectionallink can cause problems such as spanning tree protocol (STP) loops.Unidirectional links can be caused byz Fiber cross-connection, as shown in Figure 1-1z Fibers that are not connected or disconnected, as shown in Figure 1-2, the hollowlines in which refer to fibers that are not connected or disconnected.Device link detection protocol (DLDP) can detect the link status of an optical fiber cableor copper twisted pair (such as super category 5 twisted pair). If DLDP finds aunidirectional link, it disables the related port automatically or prompts you to disable itmanually according to the configurations, to avoid network problems.SwitchBSwitchAPCGE1/1/1SwitchBSwitchAPCSwitchBSwitchAPCSwitchBSwitchAPCGE1/1/1GE1/1/2GE1/1/2Figure 1-1 Fiber cross-connection
