1-1
1
DLDP Configuration
When configuring DLDP, go to these sections for information you are interested in:
z
Overview
z
DLDP Fundamentals
z
DLDP Configuration
z
DLDP Configuration Example
Overview
Device link detection protocol (DLDP) is an technology for dealing with unidirectional links that may
occur in a network.
If two switches, A and B, are connected via a pair of optical fiber cables, one used for sending from A to
B, the other sending from B to A, it is a bidirectional link (two-way link). If one of these fibers gets broken,
this is a unidirectional link (one-way link).
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 network loops.
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 are broken, as shown in
Figure 1-2
, the hollow lines in which refer
to fibers that are not connected or are broken.
Figure 1-1
Fiber cross-connection
Device A
GE1/0/49
GE1/0/50
Device B
GE1/0/49
GE1/0/50
PC
