H3C S5100-SI Series Operation Manual page 202

Operation Manual – DLDP
H3C S5100-SI/EI Series Ethernet Switches
Entry aging timer
Enhanced timer
Delaydown timer
III. DLDP operating mode
DLDP can operate in two modes: normal mode and enhanced mode.
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.
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.
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. The Delaydown timer is
configurable and ranges from 1 to 5 seconds.
A device in the delaydown state only responds to port
up messages.
A device in the delaydown state resumes its original
DLDP state if it receives a port up message before the
delaydown timer expires. Otherwise, it removes the
DLDP neighbor information and changes to the inactive
state.
Description
1-4
Chapter 1 DLDP Configuration