Networking situation:

Failure phenomenon: OSN1500 equipment EMS4 single board Vctrunk port enable loop detection and loop port shutdown function, OSN500 equipment Port3 port before the loopback, both services are through, Port3 port after the loopback, Port2 service is not available

Alarm information

ETHOAM_VCG_SELF_LOOP is reported on the Vctrunk3 port of the EMS4 single board of OSN1500 device with the parameter 01 00 02 01 FF.

Processing

1. After the MAC loopback, verify that the OSN1500 device learns the MAC address from itself and cannot learn the MAC address of the Vctrunk2 port, suspecting that the loop port shutdown function is not working;

2. Check the RMON performance of the Vctrunk3 port on the EMS4 board of the OSN1500 device, and there are no incoming and outgoing packets, which indicates that there is no problem with the loop port shutdown function;

3. Check the RMON performance of the Port2 port of the EFT single board of the OSN500 device, and there is no incoming or outgoing packet, which means that S3700 has not sent packets to the transmission device;

4, digital communication professional engineers to help analyze the reasons for S3700 did not send packets, found that the S3700 device opens the STP function, when the network is detected to have a loop, the port is closed resulting in no packets sent;

5. After closing the STP function of S3700 equipment, the service is normal.

Solution

Avoidance measures: 1. When configuring private network services, loopback operation is not allowed, which is likely to cause broadcast storms and affect the services. 2. For the networking situation in this case, if loopback operation is required, not only should the loop detection and loop port shutdown functions of the transmission-side equipment be turned on, but the STP function on the switch side also needs to be turned off.

The related technical information and SDH equipment troubleshooting procedures in this chapter are collected and organized by Shenzhen Optical Transmission Network Technology Company Limited ( www.opticaltrans.com), please retain! Our company specializes in the sale of Huawei SDH optical transmission equipment, SDH transmission equipment.