MAGNUM 6K SWITCHES, MNS-6K USER GUIDE
179
FIGURE 93 – A fault in the ring interrupts traffic. The blocking port now becomes forwarding so that
traffic can reach all switches in the network Note – the mP62 as well as the ESD42 switches support LLL
and can participate in S-Ring as an access switch
When this change is made by RSTP/STP and both of the ring manager switch’s ring ports
are forwarding, the fault is effectively bypassed and there is a path for all LAN traffic to be
handled properly. This abnormal status is designated RING_OPEN, and may continue
indefinitely, until the ring fault is repaired. At that time, RSTP/STP will change one of the
ring control ports to be a blocking port again. This recovery operation may take thirty
seconds to a few minutes, depending on the number of switches and other RSTP/STP
parameters in operation.
RSTP/STP Operation with S-Ring When the Magnum 6K family of switches is used in the network and the S-Ring feature is
enabled, the result of a ring-fault is the same but the recovery is faster. The S-Ring capability
overrides 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 standard
RSTP/STP.
The Magnum 6K family of switches, running MNS-6K software, offer users the choice of
selecting S-Ring when RSTP or STP is configured and in use. For the S-Ring, the user must
select two ports of one 6K switch to operate as a pair in support of each Ethernet ring, and
attach to the two “ends” of each ring as it comes together at the ring control switch.
BPDU
Traffic
Forwarding
Port
Forwarding
Port
X
BPDU
Traffic
BPDU
Traffic
Forwarding
Port
Forwarding
Port