Troubleshooting - 3Com Switch 4800G 24-Port Configuration Manual

Troubleshooting

# Check the information about DLDP.
[DeviceA] display dldp
DLDP global status : enable
DLDP interval : 6s
DLDP work-mode : enhance
DLDP authentication-mode
DLDP unidirectional-shutdown : auto
DLDP delaydown-timer : 2s
The number of enabled ports is 2.
Interface GigabitEthernet1/0/50
DLDP port state : disable
DLDP link state : down
The neighbor number of the port is 0.
Interface GigabitEthernet1/0/51
DLDP port state : disable
DLDP link state : down
The neighbor number of the port is 0.
The output information indicates that both GigabitEthernet1/0/50 and
GigabitEthernet1/0/51 are in Disable state and the links are down, which means
unidirectional links are detected and the two ports are thus shut down.
# Reset DLDP state for the ports shut down by DLDP.
[DeviceA] dldp reset
2 Configuration on Device B
The configuration on Device B is the same as that on Device A and is thus omitted.
n
If two fibers are cross-connected, all the four ports involved will be shut down by
DLDP.
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.
: none
Troubleshooting 195