Dldp Fundamentals - H3C S5100-SI Series Operation Manual

Operation Manual – DLDP
H3C S5100-SI/EI Series Ethernet Switches
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Figure 1-2 Fiber broken or not connected
DLDP provides the following features:
As a link layer protocol, it works together with the physical layer protocols to
monitor the link status of a device.
The auto-negotiation mechanism at the physical layer detects physical signals and
faults. DLDP identifies peer devices and unidirectional links, and disables
unreachable ports.
Even if both ends of links can work normally at the physical layer, DLDP can detect
whether these links are connected correctly and whether packets can be
exchanged normally at both ends. However, the auto-negotiation mechanism
cannot implement this detection.
Note:
In order for DLDP to detect fiber disconnection in one direction, you need to
configure the port to work in mandatory full duplex mode at a mandatory rate.
When the port determines the duplex mode and speed through auto-negotiation,
even if DLDP is enabled, it does not take effect when the fiber in one direction is
disconnected. In this case, the port is considered down.

1.1.2 DLDP Fundamentals

I. DLDP status
A link can be in one of these DLDP states: initial, inactive, active, advertisement, probe,
disable, and delaydown.
SwitchA
SwitchB
Host
1-2
Chapter 1 DLDP Configuration
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