Example for Configuring DLDP to Detect a Disconnected Optical Fiber Link

Networking Requirements

As shown in Figure 1, SwitchA and SwitchB are connected through a pair of optical fibers. On an optical fiber, Rx indicates the receive end, and Tx indicates the transmit end. The requirement is to detect unidirectional links.

Figure 1 Correct optical fiber connections

Configuration Roadmap

Configure the interfaces on both ends to work in non-auto-negotiation mode.
Enable DLDP to detect unidirectional links between SwitchA and SwitchB.
Adjust DLDP parameters to detect unidirectional links more efficiently.

Procedure

Configure the interfaces on SwitchA to work in non-auto negotiation mode.

<HUAWEI> system-view
[HUAWEI] sysname SwitchA
[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] undo negotiation auto
[SwitchA-GigabitEthernet0/0/1] quit

Enable DLDP globally.
```
[SwitchA] dldp enable
```

Enable DLDP on an interface of SwitchA.

[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] dldp enable
[SwitchA-GigabitEthernet0/0/1] quit

Set the interval for sending Advertisement packets to 10 seconds on SwitchA.
```
[SwitchA] dldp interval 10
```
Set the timeout value of the DelayDown timer to 4 seconds on SwitchA.
```
[SwitchA] dldp delaydown-timer 4
```
Set the authentication mode of DLDPDUs to sha password authentication and set the password to 12345 on SwitchA.
```
[SwitchA] dldp authentication-mode sha 12345
```
Perform steps 1 to 6 on SwitchB.

Verify the configuration.

After the configuration is complete, run the display dldp command in the interface view. The command output shows that the DLDP status of the interface is advertisement.

[SwitchA] display dldp

DLDP global status: enable
DLDP interval: 10s
DLDP work-mode: enhance
DLDP authentication-mode: sha, password is ******
DLDP unidirectional-shutdown: auto
DLDP delaydown-timer: 4s
The number of enabled ports is: 1
The number of global neighbors is: 1
The max number of global neighbors is: 512
Interface GigabitEthernet0/0/1
 DLDP port state: advertisement
 DLDP link state: up
 The neighbor number of the port is: 1.
   Neighbor mac address:80fb-0636-792d                                          
   Neighbor port index:49                                                       
   Neighbor state:two way                                                       
   Neighbor aged time(s):16

Simulate an optical fiber disconnection by removing the receive optical fiber from SwitchA. DLDP automatically shuts down GE0/0/1 on SwitchB when a unidirectional link occurs between SwitchA and GE0/0/1 on SwitchB.

# Run the display dldp command on SwitchA and SwitchB. The command output shows that the DLDP status of GE0/0/1 on SwitchA is inactive, and the DLDP status of GE0/0/1 on SwitchB is disable.

[SwitchA] display dldp interface gigabitethernet 0/0/1
Interface GigabitEthernet0/0/1                                                  
 DLDP port state: inactive                                                      
 DLDP link state: down                                                          
 The neighbor number of the port is: 0.

[SwitchB] display dldp interface gigabitethernet 0/0/1
Interface GigabitEthernet0/0/1                                                  
 DLDP port state: disable                                                      
 DLDP link state: up                                                          
 The neighbor number of the port is: 0.

Configuration Files

SwitchA configuration file

#
sysname SwitchA
#
dldp enable
dldp interval 10
dldp delaydown-timer 4
dldp authentication-mode sha %#%#x=4::bbwY1`:YhJ/e*kK_I:ONJ|CYMO/=^0QyZXEfr0xL'5Md,<4Dl:`za$9%#%#
#
interface GigabitEthernet0/0/1
 undo negotiation auto
 dldp enable
#
return

SwitchB configuration file

#
sysname SwitchB
#
dldp enable
dldp interval 10
dldp delaydown-timer 4
dldp authentication-mode sha %#%#|I<VLDbQrWDa"<!e'7WVN,l%(t0ga;&{$r,Mrq*<!,}(C|oZXAz1!gIH}*x:%#%#
#
interface GigabitEthernet0/0/1
 undo negotiation auto
 dldp enable
#
return