H3C Technologies H3C S7500E Series Switches - Manual (Page 67)

6-17
The output indicates that both GigabitEthernet 2/0/1 and GigabitEthernet 2/0/2 are in Advertisement
state, which means both links are bidirectional.
# Enable system information monitoring on Device A, and enable the display of log and trap
information.
[DeviceA] quit
terminal monitor
terminal logging
terminal trapping
The following log and trap information is displayed on Device A:
#Jan 18 17:36:18:798 2010 DeviceA DLDP/1/TrapOfUnidirectional: -Slot=2;
h3cDLDPUnidirectionalPort : DLDP detects a unidirectional link in port 17825792.
%Jan 18 17:36:18:799 2010 DeviceA IFNET/3/LINK_UPDOWN: GigabitEthernet2/0/1 link status is
DOWN.
%Jan 18 17:36:18:799 2010 DeviceA DLDP/3/DLDP_UNIDIRECTION_AUTO: -Slot=2; DLDP detects a
unidirectional link on port GigabitEthernet2/0/1. The transceiver has malfunction in the
Tx direction or cross-connected links exist between the local device and its neighbor. The
shutdown mode is AUTO. DLDP shuts down the port.
#Jan 18 17:36:20:189 2010 DeviceA DLDP/1/TrapOfUnidirectional: -Slot=2;
h3cDLDPUnidirectionalPort : DLDP detects a unidirectional link in port 17825793.
%Jan 18 17:36:20:189 2010 DeviceA IFNET/3/LINK_UPDOWN: GigabitEthernet2/0/2 link status is
DOWN.
%Jan 18 17:36:20:190 2010 DeviceA DLDP/3/DLDP_UNIDIRECTION_AUTO: -Slot=2; DLDP detects a
unidirectional link on port GigabitEthernet2/0/2. The transceiver has malfunction in the
Tx direction or cross-connected links exist between the local device and its neighbor. The
shutdown mode is AUTO. DLDP shuts down the port.
%Jan 15 16:54:56:040 2010 DeviceA DLDP/3/DLDP_UNIDIRECTION_AUTO_ENHANCE: -Slot=2; In
enhanced DLDP mode, port GigabitEthernet2/0/1 cannot detect its aged-out neighbor. The
transceiver has malfunction in the Tx direction or cross-connected links exist between the
local device and its neighbor. The shutdown mode is AUTO. DLDP shuts down the port.
The output above indicates that the link status of both GigabitEthernet 2/0/1 and GigabitEthernet 2/0/2
is down, and DLDP has detected a unidirectional link on both ports and has automatically shut them
down.
Assume that in this example, the unidirectional links are caused by cross-connected fibers. Correct
the fiber connections on detecting the unidirectional link problem. As a result, the ports shut down by
DLDP automatically recover, and Device A displays the following log information:
%Jan 18 17:47:33:869 2010 DeviceA IFNET/3/LINK_UPDOWN: GigabitEthernet2/0/1 link status is
UP.
%Jan 18 17:47:35:894 2010 DeviceA IFNET/3/LINK_UPDOWN: GigabitEthernet2/0/2 link status is
UP.
The output above indicates that the link status of both GigabitEthernet 2/0/1 and GigabitEthernet 2/0/2
is now up.
Manually Shutting Down Unidirectional Links
Network requirements
z As shown in Figure 6-4 , Device A and Device B are connected with two fiber pairs.