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3. Troubleshooting Functional Failures in Operation
119
3.18 Communication Failure on IEEE802.3ah/UDLD
Function
3.18.1 Port Becomes Inactive Due to IEEE802.3ah/UDLD Function
If the port becomes inactive due to IEEE802.3ah/UDLD function, isolate the problem by following failure analysis
methods shown in the table below.
Table 3-66: Failure Analysis Method When IEEE802.3ah/UDLD Function Is in Use
Note:
IEEE802.3ah/OAM: OAM protocol specified by IEEE802.3ah.
IEEE802.3ah/UDLD: One-way link failure detection function specific to this system using IEEE802.3ah/OAM.
No. Troubleshooting Steps and Command Action
1Use the show efmoam command to check the
failure type of the port which becomes inactive
due to IEEE802.3ah/UDLD function.
If "Down(loop)" is displayed in Link status, the network configuration which
causes L2 loop may be adopted. Review the network configuration.
If "Down(uni-link)" is displayed in Link status, go to No. 2.
2 Check that IEEE802.3ah/OAM function is
enabled in the opposite system.
If not enabled, enable IEEE802.3ah/OAM function in the opposite system.
If enabled, go to No. 3.
3 Execute the show efmoam statistics
command to check the inhibited configuration
is not adopted.
If Unstable of Info TLV has been incremented, the configuration inhibited
for IEEE802.3ah/UDLD function may be adopted. Check that the physical
port is connected to only one system.
If Unstable of Info TLV has not been incremented, go to No. 4.
4 Check that the system is directly connected to
the opposite system.
If the system is connected through the media converter or hub, review the
network configuration so that it is directly connected to the opposite system.
If it cannot be avoided to use some relay equipment, use the media converter
which enables the linkage status to be same at both sides (however, not
recommended).
If the system is directly connected to the opposite system, go to No. 5.
5 Execute the show efmoam command to check
the number of response timeout times for
detecting the failure.
If the value of "udld-detection-count" is less than the initial value, the
possibility that the one-way link failure is detected erroneously in spite of no
actual failure is raised. Change the value of "udld-detection-count."
If the value of "udld-detection-count" exceeds the initial value, go to No. 6.
6 Check settings of the filter and QoS control. Control frames (slow-protocol) used by IEEE802.3ah/UDLD function may
have been discarded by filtering or QoS control.
See "3.23.1 Checking Filtering/QoS Setting Information" to check for it. If
there is no problem, go to No. 7.
7 Test the line. Test the line by referencing "6.1 Testing Line." If there is no problem, go to
No. 8.
8 Check the cable. Cable may be defective. Replace the cable used at the port.