According to the customer’s maintenance engineer working at the equipment room, the red alarm indicator was often on for LPU 2 of the NE40E.
The alarms generated by the device were collected as follows:
Jul 31 2008 15:54:01 TZ-XQ-R-NE40E-01 %%01SRM/2/TMLINEERR(l): LPU2 occur line error! Error Code=2.2!
Jul 31 2008 15:53:01 TZ-XQ-R-NE40E-01 %%01SRM/2/TMLINEERR(l): LPU2 occur line error! Error Code=2.1!
After the port mirroring configuration was deleted, the problem was solved.
1. The alarms were generated because packets were lost on LPU 2.
2. Checking GE 2/0/4, the engineer found the following information, indicating that the port was almost fully loaded with the traffic:
Last 30 seconds output rate: 968093056 bits/sec, 209961 packets/sec
3. Checking the configuration, the engineer found the device was configured with port mirroring. GE 2/0/4 was the monitoring port, whereas GE 1/0/0 and GE 2/0/0 were mirroring ports. During the busy hours, when the traffic on the two mirroring ports added up to more than 1 Gbit/s, the traffic overflowed and back pressure occurred on LPU 2, hence the alarms.
When multiple mirroring ports were configured to mirror the traffic to one monitoring port, note the traffic on the mirroring ports.