1-5
Table 1-4
Types of packets sent by DLDP
DLDP status
Packet types
Active
Advertisement packets, including those with or without RSY tags
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packets
Probe Probe
packets
2) DLDP analyzes and processes received packets as follows:
z
In authentication mode, DLDP authenticates the packets, and discards those do not pass the
authentication.
z
DLDP processes the received DLDP packets.
Table 1-5
Process received DLDP packets
Packet type
Processing procedure
If this neighbor entry does not exist on the local device,
DLDP creates the neighbor entry, enables the entry
aging timer, and turns to probe status.
Advertisement
packet
Extract neighbor
information
If the neighbor entry already exists on the local device,
DLDP refreshes the entry aging timer.
Flush packet
Delete the neighbor entry from the local device
Create the neighbor entry if this neighbor entry does not
exist on the local device.
Probe packet
Send echo packets
containing both
neighbor and its own
information to the
peer
If the neighbor entry already exists on the local device,
refresh the entry aging timer.
No
Discard this echo packet
No
Discard this echo packet
Set the neighbor flag bit to
bidirectional
Echo packet
Check
whether the
local device
is in probe
status
Yes
Check
whether
neighbor
information in
the packet is
the same as
that on the
local device
Yes
If all neighbors are in
bidirectional communication
state, DLDP turns from probe
status to advertisement status,
and sets the echo waiting timer
to 0.
3) If no echo packet is received from the neighbor, DLDP performs the following processing:
Table 1-6
Processing when no echo packet is received from the neighbor
No Echo packet received from the
neighbor
Processing procedure
In normal mode, no echo packet is received
when the echo waiting timer expires
In enhanced mode, no echo packet is
received when the enhanced timer expires
DLDP turns into disable status. It outputs log and
tracking information, sends flush packets. Depending
on the user-defined DLDP down mode, DLDP
disables the local port automatically or prompt the
user to disable the port manually. DLDP sends the
RSY message and deletes the neighbor entry.
