H3C S7500 Series Ethernet Switches Operation Manual

Operation Manual – DLDP
H3C S7500 Series Ethernet Switches Chapter 1
DLDP Configuration
1-8
Timer Description
DelayDown
timer
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.
1.2.4 DLDP Operating Mode
DLDP can operate in two modes: normal and enhanced.
Table 1-7 DLDP operating mode and neighbor entry aging
DLDP
operating
mode
DLDP detects whether
neighbors exist or not
when neighbor tables
are aging
The entry aging
timer is enabled or
not during neighbor
entry aging
The enhanced
timer is enabled
or not when the
entry aging timer
expires
Normal
mode
No
Yes (The neighbor
entry ages out after
the entry aging timer
expires)
No
Enhanced
mode
Yes
Yes (The enhanced
timer is enabled after
the entry aging timer
expires)
Yes (When the
enhanced timer
expires, the state
of the local end is
set to
unidirectional link,
and the neighbor
entry is aged out.)
1.2.5 DLDP Neighbor State
A DLDP neighbor can be in one of these two states: two way and unknown. You can
check the state of a DLDP neighbor by using the display dldp command.