TP-Link T2600G-28MPS T2600G-28MPSUN V1 User Guide - Page 144

DLDP Operation Mechanism

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spanning-tree topology loops. Once detecting a unidirectional link, DLDP can shut down the related port automatically or inform users.  DLDP Operation Mechanism 1. DLDP Link States DLDP defines 6 link states for a device:Initial, Inactive, Active, Advertisement, Probe and Disable. State Initial Inactive Active Advertisement Probe Disable Description DLDP is disabled. DLDP is enabled but the link is down. This state is temporary and it indicates that: 1. DLDP is enabled and the link is up. 2. The neighbor entries in this device are empty. 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. 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. 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: ○1 : When DLDP is enabled on the link in down state, the DLDP link state will transit to Inactive. E A ○2 : When the DLDP-enabled link is up, the DLDP link state will transit to Active. The device will A E A send out Advertisement packets to the peer device with resynchronization tag in this state. 133

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spanning-tree topology loops. Once detecting a unidirectional link, DLDP can shut down the
related port automatically or inform users.
DLDP Operation Mechanism
1. DLDP Link States
DLDP defines 6 link states for a device
Initial, Inactive, Active, Advertisement, Probe and Disable.
State
Description
Initial
DLDP is disabled.
Inactive
DLDP is enabled but the link is down.
Active
This state is temporary and it indicates that:
1. DLDP is enabled and the link is up.
2. The neighbor entries in this device are empty.
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:
1
: When DLDP is enabled on the link in down state, the DLDP link state will transit to Inactive.
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.
133