3Com WX3000 Series Operation Manual page 155

Table 1-4 Types of packets sent by DLDP
DLDP status
Active
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Probe
2) DLDP analyzes and processes received packets as follows:
In authentication mode, DLDP authenticates the packets, and discards those do not pass the
authentication.
DLDP processes the received DLDP packets.
Table 1-5 Process received DLDP packets
Packet type
Advertisement Extract neighbor
packet information
Flush packet Delete the neighbor entry from the local device
Send echo packets
containing both
Probe packet
neighbor and its own
information to the
peer
Check
whether the
Echo packet local device
is in probe
status
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
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
Advertisement packets, including those with or without RSY tags
Advertisement packets
Probe packets
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.
If the neighbor entry already exists on the local device,
DLDP refreshes the entry aging timer.
Create the neighbor entry if this neighbor entry does not
exist on the local device.
If the neighbor entry already exists on the local device,
refresh the entry aging timer.
No Discard this echo packet
Check
whether
neighbor
information in
Yes
the packet is
the same as
that on the
local device
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.
1-5
Packet types
No Discard this echo packet
Set the neighbor flag bit to
bidirectional
If all neighbors are in
bidirectional communication
Yes
state, DLDP turns from probe
status to advertisement status,
and sets the echo waiting timer
to 0.
Processing procedure