3Com S7902E, Configuration Manual

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1-8
RecoverEcho packet. Upon receiving the RecoverEcho packet, the local port checks whether neighbor
information in the RecoverEcho packet is the same as the local port information. If they are the same,
the link between the local port and the neighbor is considered to have been restored to a bidirectional
link, and the port will transit from Disable state to Active state and re-establish neighborship with the
neighbor.
Only DLDP down ports can send and process Recover packets, including RecoverProbe packets and
RecoverEcho packets. The auto-recovery mechanism does not take effect on ports manually shut
down.
DLDP neighbor state
A DLDP neighbor can be in one of the three states described in Table 1-7 .
Table 1-7 Description on DLDP neighbor states
DLDP neighbor
state
Description
Unknown
A neighbor is in this state when it is just detected and is being probed. No
information indicating the state of the neighbor is received. A neighbor is in
this state only when it is being probed. It transits to Two way state or
Unidirectional state after the probe operation finishes.
Two way
A neighbor is in this state after it receives response from its peer. This state
indicates the link is a two-way link.
Unidirectional
A neighbor is in this state when the link connecting it is detected to be a
unidirectional link. After a device transits to this state, the corresponding
neighbor entries maintained on other devices are removed.
DLDP Configuration Task List
Complete the following tasks to configure DLDP:
Task Remarks
Enabling DLDP Required
Setting DLDP Mode Optional
Setting the Interval for Sending Advertisement Packets Optional
Setting the DelayDown Timer Optional
Setting the Port Shutdown Mode Optional
Configuring DLDP Authentication Optional
Resetting DLDP State Optional
Note that:
z
DLDP takes effects only on Ethernet interfaces.
z
DLDP can detect unidirectional links only after all links are connected. Therefore, before enabling
DLDP, make sure that optical fibers or copper twisted pairs are connected.
z
To ensure unidirectional links can be detected, make sure these settings are the same on the both
sides: DLDP state (enabled/disabled), the interval for sending Advertisement packets,
authentication mode, and password.