R3102-R3103-HP 6600/HSR6600 Routers High Availability Configuration Guide

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Table 15 Processing incoming DLDP packets by packet type
Packet type
Processing procedure
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Retrieves the
neighbor
information.
If no matching neighbor entry exists, creates the neighbor
entry, triggers the Entry timer, and changes the DLDP port state
to Probe.
If a matching neighbor entry already exists, resets the Entry
timer and changes the DLDP port state to Probe.
Normal
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Retrieves the
neighbor
information.
If no matching neighbor entry exists, creates the neighbor
entry, triggers the Entry timer, and changes the DLDP port state
to Probe.
If a matching neighbor entry already exists, resets the Entry
timer.
Flush packet
Checks whether the
local DLDP port state
is Disable.
If yes, performs no processing.
If no, removes the matching neighbor entry (if any).
Probe
Retrieves the
neighbor
information.
If no matching neighbor entry exists, creates the neighbor
entry, transits to the Probe state, and returns Echo packets.
If a matching neighbor entry already exists, resets the Entry
timer and returns Echo packets.
Echo
Retrieves the
neighbor
information.
If no matching neighbor entry exists, creates the neighbor
entry, triggers the Entry timer, and changes the DLDP port state
to Probe.
If a matching neighbor entry already exists:
 Drops the packet if it carries information that conflicts with
the neighbor entry.
 Otherwise, sets the state of the neighbor to two way
(bidirectional). If all the neighbors are in two way state,
changes from the Probe state to the Advertisement state
and disable the Echo timer.
Disable
Checks whether the
local DLDP port state
is Disable.
If yes, no process is performed.
If no, sets the state of the neighbor to one way (unidirectional),
and then checks the state of other neighbors to determine the
subsequent action to take:
 If all the neighbors are in one way state, changes the local
DLDP port state to Disable.
 If the state of some neighbors is still unknown, takes no
action until the state of these neighbors is determined.
 If any two-way neighbor is present, removes all one-way
neighbors, but does not change the DLDP port state.
RecoverProbe
Checks whether the
local port is in
Disable or
Advertisement state.
If yes, returns RecoverEcho packets.
If no, no process is performed.
RecoverEcho
Checks whether the
local DLDP port state
is Disable.
If yes, changes the local DLDP port state to Active if the
neighbor information the packet carries is consistent with the
local port information.
If no, no process is performed.