M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D E179FIGURE 93 – A fault in the ring interrupts traffic. The blocking port now becomes forwarding so thattraffic can reach all switches in the network Note – the mP62 as well as the ESD42 switches support LLLand can participate in S-Ring as an access switchWhen this change is made by RSTP/STP and both of the ring manager switch’s ring portsare forwarding, the fault is effectively bypassed and there is a path for all LAN traffic to behandled properly. This abnormal status is designated RING_OPEN, and may continueindefinitely, until the ring fault is repaired. At that time, RSTP/STP will change one of thering control ports to be a blocking port again. This recovery operation may take thirtyseconds to a few minutes, depending on the number of switches and other RSTP/STPparameters in operation.RSTP/STP Operation with S-RingWhen the Magnum 6K family of switches is used in the network and the S-Ring feature isenabled, the result of a ring-fault is the same but the recovery is faster. The S-Ring capabilityoverrides the normal RSTP/STP analysis for the ring-pair ports of the ring manager (or ring-control) switch, providing quick recovery of the ring fault without conflicting with standardRSTP/STP.The Magnum 6K family of switches, running MNS-6K software, offer users the choice ofselecting S-Ring when RSTP or STP is configured and in use. For the S-Ring, the user mustselect two ports of one 6K switch to operate as a pair in support of each Ethernet ring, andattach to the two “ends” of each ring as it comes together at the ring control switch.BPDUTrafficForwardingPortForwardingPortXBPDUTrafficBPDUTrafficForwardingPortForwardingPortXBPDUTraffic
