H3C Technologies H3C S3600 Series Switches - Manual (Page 221)

1-1
1
DLDP Configuration
When configuring DLDP, go to these sections for information you are interested in:
z Overview
z DLDP Configuration
z DLDP Configuration Example
Overview
Introduction
A special kind of links, namely, unidirectional links, may occur in a network. When a unidirectional link
appears, the local device can receive packets from the peer device through the link layer, but the peer
device cannot receive packets from the local device. Unidirectional link can cause problems such as
loops in a Spanning Tree Protocol (STP) enabled network.
As for fiber links, two kinds of unidirectional links exist:
z Fiber cross-connection, as shown in Figure 1-1
z Fibers that are not connected or disconnected, as shown in Figure 1-2 , the hollow lines in which
refer to fibers that are not connected or disconnected.
The Device Link Detection Protocol (DLDP) can detect the link status of an optical fiber cable or copper
twisted pair (such as super category 5 twisted pair). If DLDP finds a unidirectional link, it disables the
related port automatically or prompts you to disable it manually according to the configurations, to avoid
network problems.
Figure 1-1 Fiber cross-connection
Switch A
GE1/1/3 GE1/1/4
Switch B
GE1/1/3 GE1/1/4
Host