GarrettCom Magnum MNS-6K - Manual (Page 157)

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 E
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F IGURE 85 – 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.
BPD
U
Tra
ffic
Forwarding
Port
Forwarding
Port
X
B
P
D
U
T
ra
ff
ic
BPD
U
Tra
ffic
Forwarding
Port
Forwarding
Port
X
B
P
D
U
T
ra
ff
ic