Operation Manual

139
State
Description
Advertisement This state indicates that no unidirectional link is detected, which includes
two kinds of situations:
1. This device establishes bidirectional links with all its neighbors.
2. DLDP remains in Active state for more than 5 seconds.
Probe A device enters this state from the Active state if it receives a packet from
an unknown neighbor. In this state, the device will send out Probe packets
to detect whether the link is unidirectional.
Disable
This state indicates that a unidirectional link is detected.
Table 8-3 DLDP Link State
2. DLDP Work Process
The general DLDP work process chart is shown below:
Figure 8-11 DLDP Process
The process is illustrated below:
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1 : When DLDP is enabled on the link in down state, the DLDP link state will transit to Inactive.
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2 : When the DLDP-enabled link is up, the DLDP link state will transit to Active. The device will
send out Advertisement packets to the peer device with resynchronization tag in this state.
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3 : If the device doesn’t receive any DLDP packets within 5 seconds, the DLDP link state will
transit to Advertisement.
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4 : After receiving a packet from an unknown neighbor, the device’s link state will transit from
Active to Probe, and then send out several probe packets to detect the link state.
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5 : If the device receives echo packets from its peer device, the link state between them will be
tagged as bidirectionally linked and the DLDP state will transit from Probe to Advertisement. A
device in the Advertisement state will send advertisement packets.