3Com 4510G Configuration Manual page 820

Neighbor aged time : 11
Interface GigabitEthernet1/0/51
DLDP port state : advertisement
DLDP link state : up
The neighbor number of the port is 1.
Neighbor mac address : 0000-0000-0102
Neighbor port index : 59
Neighbor state : two way
Neighbor aged time : 11
The output information indicates that both GigabitEthernet 1/0/50 and GigabitEthernet 1/0/51 are in
Advertisement state and the links are up, which means unidirectional links are not detected and the
two ports are restored.
Troubleshooting
Symptom:
Two DLDP-enabled devices, Device A and Device B, are connected through two fiber pairs, in which
two fibers are cross-connected. The unidirectional links cannot be detected; all the four ports involved
are in Advertisement state.
Analysis:
The problem can be caused by the following.
The intervals for sending Advertisement packets on Device A and Device B are not the same.
DLDP authentication modes/passwords on Device A and Device B are not the same.
Solution:
Make sure the interval for sending Advertisement packets, the authentication mode, and the password
on Device A and Device B are the same.
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