Phenomenon Description

At a bureau point, Huawei digital communication switches are networked with OptiX OSN1500 devices, and the topology of the four digital communication switches is a ring structure. The two end bureau points are two S6506 switches and two S3528 switches. After starting the STP protocol on the Numeric Communication switches, the network is found to be divided into two domains, and packet loss is found by counting the packets sent and received on the switch ports.

Cause Analysis

Since there is a clear record of outgoing packets but no record of incoming packets on the Numeric Communication device. It can be basically determined that the packets are dropped on the OptiX OSN device.

The generalized STP protocol has three modes: MSTP (Multiple Spanning Tree Protocol), RSTP (Rapid Spanning Tree Protocol) and STP (Spanning Tree Protocol).

The STP protocol mode of some digital communication devices is MSTP by default, while OptiX OSN devices support only RSTP and STP protocols.

The current packet loss is mainly caused by the inconsistency of the STP protocol mode when Huawei Digital Communication Switches are interfaced with OptiX OSN1500 devices.

Processing Procedure

Change the STP protocol mode of the switch to RSTP, and the fault disappears.