H3C Technologies H3C S3100 Series Switches - Manual (Page 194)

1-5
Status Description
DelayDown
When a device in the active, advertisement, or probe DLDP state
receives a port down message, it does not removes the
corresponding neighbor immediately, neither does it changes to the
inactive state. Instead, it changes to the delaydown state first.
When a device changes to the delaydown state, the related DLDP
neighbor information remains, and the DelayDown timer is triggered.
After the DelayDown timer expires, the DLDP neighbor information is
removed.
DLDP Timers
Table 1-3 DLDP timers
Timer Description
Advertisement sending
timer
Interval between sending advertisement packets, which can be
configured on a command line interface.
By default, the timer length is 5 seconds.
Probe sending timer
The interval is 0.5 seconds. In the probe state, DLDP sends two probe
packets in a second.
Echo waiting timer
It is enabled when DLDP enters the probe state. The echo waiting
timer length is 10 seconds.
If no echo packet is received from the neighbor when the Echo waiting
timer expires, the state of the local end is set to unidirectional link
(one-way audio) and the state machine turns into the disable state.
DLDP outputs log and tracking information, sends flush packets.
Depending on the user-defined DLDP down mode, DLDP disables
the local port automatically or prompts you to disable the port
manually. At the same time, DLDP deletes the neighbor entry.
Entry aging timer
When a new neighbor joins, a neighbor entry is created and the
corresponding entry aging timer is enabled
When an advertisement packet is received from a neighbor, the
neighbor entry is updated and the corresponding entry aging timer is
updated
In the normal mode, if no packet is received from the neighbor when
the entry aging timer expires, DLDP sends an advertisement packet
with an RSY tag, and deletes the neighbor entry.
In the enhanced mode, if no packet is received from the neighbor
when the entry aging timer expires, DLDP enables the enhanced
timer
The entry aging timer length is three times the advertisement timer
length.
Enhanced timer
In the enhanced mode, if no packet is received from the neighbor
when the entry aging timer expires, DLDP enables the enhanced
timer for the neighbor. The enhanced timer length is 10 seconds
The enhanced timer then sends one probe packet every second and
eight packets successively to the neighbor.
If no echo packet is received from the neighbor when the enhanced
timer expires, the state of the local end is set to unidirectional
communication state and the state machine turns into the disable
state. DLDP outputs log and tracking information and sends flush
packets. Depending on the user-defined DLDP down mode, DLDP
disables the local port automatically or prompts you to disable the port
manually. Meanwhile, DLDP deletes the neighbor entry.