Dldp Operating Mode - H3C S5100-SI Operation Manual

Timer
Entry aging timer
Enhanced timer
DelayDown timer

DLDP Operating Mode

DLDP can operate in two modes: normal mode and enhanced mode.
Table 1-4 DLDP operating mode and neighbor entry aging
DLDP detects whether
DLDP
neighbors exist or not
operating
when neighbor tables
mode
Normal
No
mode
Enhanced
Yes
mode
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.
The entry aging timer
is enabled or not
during neighbor entry
are aging
Yes (The neighbor entry
ages out after the entry
aging timer expires)
Yes (The enhanced
timer is enabled after
the entry aging timer
expires)
Description
The enhanced timer is enabled
or not when the entry aging
aging
No
Yes (When the enhanced timer
expires, the state of the local end
is set to unidirectional link, and
the neighbor entry is aged out.)
1-5
timer expires