Operation Mannual – RRPPH3C S7500 Series Ethernet Switches Chapter 1 RRPP Configuration1-51.1.3 Basic Principles of RRPPI. Link DOWN notification mechanismWhen detecting a port in the RRPP domain is down, a transit node sends the LINKDOWN packet immediately to the master node. After receiving the LINK DOWN packet,the master node unblocks the data VLAN of the secondary port, and sends theCommon Flush packet to tell all transit nodes to refresh their respective MAC addressFDBs.II. Polling mechanismThe primary port of the master node periodically sends the health detection packet in acontrol VLAN.z If the secondary port of the master node receives the health detection packet, thisindicates that the ring link is complete, and the master node will keep thesecondary port blocked.z If the secondary port of the master node fails to receive the health detection packetwithin the predefined timeout time, this indicates that a failure has occurred to thering link. In this case, the master node unblocks the data VLANs on the secondaryport, and sends the Common Flush packet to tell all transit nodes to refresh theirrespective MAC address FDBs.III. Ring recoveryThe master node may detect that the ring has recovered a period time after the RRPPdomain port on a transit node becomes UP again. In this period, a temporary data loopmay occur in data VLANs, which can cause broadcast storm.To avoid temporary data loops, when detecting the port through which it connects to thering network becomes UP again, a transit node blocks the port temporarily (only controlVLAN packets are permitted to pass), and keeps the port blocked until it receives theComplete Flush packet from the master node.1.1.4 Typical Networking of RRPPTo ensure normal RRPP operation, you must configure RRPP correctly. Here areseveral typical networking applications.
