Ring-shaped or other redundant links may be formed on the physical links between microwave equipment, causing loops to Layer 2 forwarding. You can configure the Rapid Spanning Tree Protocol (RSTP) to clear broadcast loops.
Context
All microwave NEs are in the subnet 129.9.1.0/24 and their data communication network (DCN) communication is implemented through Layer 2 forwarding, as shown in Figure 1. Two faults may occur on such a network:
- Broadcast loops: A data frame sent to a broadcast MAC address from the U2000 Web LCT is forwarded endlessly on this network.
- MAC address table flapping: There is a probability of MAC address table flapping even for unicast packets on this network. NE A may learn the MAC address of NE B through port 1 or port 2: NE A learns the address directly at port 1 or NE C forwards the data frame from NE B to NE A through port 2. Therefore, NE A will keep updating its MAC address table, and MAC address table flapping occurs.
Procedure
- In the NE Explorer, select an NE and choose .
- In the RSTP enabled status area, set Config Status.
NOTE: All Layer 2 DCN-enabled ports are automatically added to a group. It is recommended that the RSTP protocol uses its default enable/disable mode Auto. That is, the RSTP protocol is automatically enabled/disabled depending on the enable/disable status of the L2 DCN function over IF ports.
- Optional: Click Query to query Real Status of the RSTP protocol.