Operation Manual - DLDP 
Quidway S5600 Series Ethernet Switches-Release 1510  Chapter 1  
DLDP Configuration
 
Huawei Technologies Proprietary 
1-4 
Timer  Description 
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 normal mode, if no packet is received from the neighbor when 
the entry aging timer expires, DLDP sends an advertisement 
packet with RSY tag, and deletes the neighbor entry 
In enhanced mode, if no packet is received from the neighbor 
when the entry aging timer expires, DLDP enables the enhanced 
timer 
The interval set for the entry aging timer is three times of that for 
the advertisement timer 
Enhanced 
timer 
In 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 timeout time for the enhanced timer is 
10 seconds 
The enhanced timer then sends one probe packets every one 
second and totally eight packets continuously to the neighbor 
If no echo packet is received from the neighbor when the 
Enhanced timer expires, the local end is set to unidirectional 
communication status and the state machine turns into disable 
status. 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 prompt the user to disable 
the port manually. DLDP deletes the neighbor entry 
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. 
 
III. DLDP operating mode 
DLDP can operate in two modes: normal and enhanced.