GarrettCom MNS-6K 4.1.4 - Manual (Page 177)

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
3. There can be multiple S-Rings on a given Magnum 6K switch. There can be
multiple ring topologies in a network. Each ring has to be a separate ring. Ring
of rings or overlapping rings are not supported at this time
4. S-Ring topologies support one failure in the network. A second failure may
create isolated network islands
5. At least one untagged VLAN must be available for the BPDU’s to propagate
through the network to update RSTP/STP status
6. S-Ring faults can be software signaled to alarm contacts.
Comparing resiliency methods
So far we have briefly covered S-Ring with LLL, RSPT as well as STP. The table below
summarizes some decision criteria on selecting RSPT vs STP vs S-Ring (and LLL.)
S-Ring with LLL RSTP STP
License A license key is needed. One key
per ring manager switch Included in MNS-
6K Included in MNS-
6K
Spanning Tree
Works with RSTP or STP devices -- --
Devices
supported Managed or certain non managed
Magnum switches. Requires at least
one Magnum 6K switch as ring
manager Many Many
Recovery
decision Centralized to “Ring Manager”.
LLL provides triggers to
recomputed topology for ring
members. Also works with RSTP
or STP. Typically done
using BPDU. Can
take time. Typically done
using BPDU. Can
take time.
Topology Single ring, multiple rings, no
overlapping rings or ring of rings Mesh topology –
can have multiple
paths Mesh topology –
can have multiple
paths
Interoperability
Works with managed 6K family of
switches, other managed switches
such as mP62 and non managed
switches as well as some hubs Wide range of
products,
including other
vendor products Wider range of
products,
including other
vendor products
Recovery time
Fast Medium – sub
second to a few
seconds Slow – in tens of
seconds
176