If an upper-layer Layer 2 network is not notified of the topology change in an ERPS ring, the MAC address entries remain unchanged on the upper-layer network and therefore user traffic is interrupted. To ensure nonstop traffic transmission, configure the topology change notification function and specify the ERPS rings that will be notified of the topology change.
In addition, if an ERPS ring frequently receives topology change notifications, its nodes will have lower CPU processing capability and repeatedly update Flush-FDB packets, consuming much bandwidth. To resolve this problem, set the topology change protection interval at which topology change notifications are sent to suppress topology change notification transmission, and set the maximum number of topology change notifications that can be processed during the topology change protection interval to prevent frequent MAC address and ARP entry updates.
The system view is displayed.
The ERPS ring view is displayed.
The ERPS ring is configured to notify other ERPS rings of its topology change.
ring-id1 [ to ring-id2 ] specifies the start and end ring IDs of the ERPS rings that will be notified of the topology change. Ensure that the ERPS rings specified by ring-id1 and ring-id2 exist. If the specified rings do not exist, the topology change notification function does not take effect.
After the ERPS rings receive the topology change notification from an ERPS ring, they send Flush-FDB messages on their separate rings to instruct their nodes to update MAC addresses so that user traffic is not interrupted.
The topology change protection interval at which topology change notification messages are sent is set.
The number of times ERPS parses topology change notifications and updates forwarding entries in the topology change protection interval is set.
The topology change protection interval is the one specified by the tc-protection interval command.