1-11 DLDP ConfigurationWhen performing DLDP configuration, go to these sections for information you are interested in:z Overviewz DLDP Configuration Task Listz Enabling DLDPz Setting DLDP Modez Setting the Interval for Sending Advertisement Packetsz Setting the DelayDown Timerz Setting the Port Shutdown Modez Configuring DLDP Authenticationz Resetting DLDP Statez Displaying and Maintaining DLDPz DLDP Configuration Examplez TroubleshootingOverviewBackgroundSometimes, unidirectional links appear in networks. On a unidirectional link, one end can receivepackets from the other end but the other end cannot. For example, if two switches, Switch A and SwitchB, are connected via a fiber pair, one used for sending packets from A to B and the other for sendingpackets from B to A, the link between the two switches is a bidirectional link (two-way link). If one ofthese fibers gets broken, the link becomes a unidirectional link (one-way link).Unidirectional links result in problems such as loops in an STP-enabled network.There are two types of unidirectional fiber links. One occurs when fibers are cross-connected, and theother occurs when one end of a fiber is not connected or one fiber of a fiber pair gets broken. Figure 1-1.shows a correct fiber connection and two types of unidirectional fiber connection.
