Description of the problem

Use Huawei OSN3500 device N2EFS0 to open the large-customer aggregation service, and the downlinked data device opens the MSTP Spanning Tree Protocol, and the data service can be pinged, but the BPDU messages of the Spanning Tree Protocol between the downlinked Huawei Data Devices S3328 and S2300 are only sent packets, not received packets, and the BPDU messages cannot be communicated.

Processing

1. First, check the service configuration of the transmission side, and find that it is configured as EPLAN service, which requires that the BPDU message of the transmission equipment and the data equipment can be compatible. When RSTP is turned on at the transmission side, the service pings through, but the BPDU cannot be transmitted, and when RSTP is turned off, the service cannot ping through. This indicates that the service signals can be communicated normally after the Spanning Tree Protocol is turned on, and the transmission equipment itself is configured normally.

2, after confirming with the data, the MSTP multiple spanning tree protocol opened between S3328 and S2300 is not supported by Huawei transmission equipment, and can only support RSTP single spanning tree protocol. The best way is to dock the Spanning Tree Protocol between S3328 and S2300, and transmit for transmissions.

3, guide the user to configure the EPL service as a shared port to realize the convergence function, the EPL service BPDU message as a data service signal to transparently transmit, do not recognize and do not handle. After the modification, the fault remains the same, the downlink data devices can ping each other, but the BPDU messages cannot be transmitted.

4, suspect that the BPDU is ultra-short packet is discarded, use sniffer to capture packets, found that the BPDU is about 100 bytes, to rule out the problem of ultra-short packets.

5, and data engineers to confirm that the BPDU for the message without VLAN, that is, the data side of the signal sent over with VLAN business data also have BPDU messages without VLAN, guide the user to modify the port attributes for hybrid, the data side to see the BPDU message send and receive normal, the problem is solved.

Root Cause

1. The byte of the BPDU message is less than 64 bytes, which causes the ultra-short packet to be discarded.

2. The configured VLAN of the BPDU message is not consistent with the configured VLAN number on the transmission side.

3. Transmission side data configuration error.

4. Transmission-side and data-side spanning tree protocol compatibility issues.

Recommendations and summary

1, the data side supports MSTP multiple spanning tree protocol, while the transmission side is generally RSTP single spanning tree protocol, RSTP rapid spanning tree only for VB to port service blocking, while MSTP is for VLAN to service blocking. There will be problems with the compatibility of the two protocols. Specifically, you can query SC0000267422.

2. There are BPDU messages with VLAN and without VLAN, so you need to check clearly when configuring the service on the transmission side and make corresponding configurations according to the situation. In this example, the service signal is with VLAN, and the BPDU is without VLAN, so you need to configure the port attribute as hybrid attribute. When the BPDU with VLAN is transmitting, the BPDU is treated as a service signal, and the corresponding VLAN should be added to configure the service.

The related technical information in this chapter and the SDH equipment troubleshooting process are collected and organized by Shenzhen Optical Transmission Network Technology Co. ( www.opticaltrans.com), and are reproduced and retained! Our company specializes in the sales of Huawei SDH optical transmission equipment, SDH transmission equipment.