3Com 4500 PWR 26-Port Configuration Manual page 206

17
DLDP Configuration
Wh n configuring DLDP, g e
Overview
DLDP Configuration
DLDP Configuration Example
Overview
Introd uction
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 pee
device cannot receive packets from the local device. U
loops in a Spanning Tree Protocol (STP) enabled netwo
As for fiber links, two kinds of unidirectional links exist:
Fiber cross-connection, as shown in
Fibers that are not connected or disconnected, as shown in
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 prompt
network problems.
Figure 17-1 Fiber cross-connection
Device A
GE1/0/49
GE1/0/49
Device B
PC
o to these sections for information you are interested in:
Figure 17-1
s you to disable it manually according to the configurations, to avoid
GE1/0/50
GE1/0/50
17-1
r device through the link layer, but the peer
nidirectional link can cause problems such as
rk.
Figure 17-2, the hollow lines in which