Specifications

Extreme Networks Technical Brief
© 2010 Extreme Networks, Inc. All rights reser ved. SummitStack Stacking Technology—Page 2
SummitStack Topologies
Figure 1 presents a graphical representation of a stack and
some of the terms that describe stack conditions.
A stack is the collection of all nodes that are cabled together
in a stack.
A stack topology is the set of contiguous nodes that are
powered up and communicating with each other. Switch 8 is
not part of the stack topology in Figure 1 because it is not
powered up.
An active topology is the set of contiguous nodes that are
active. An active node is powered up, configured for
SummitStack operation, and communicating with the other
active nodes. Switch 5 in Figure 1 has failed, and stacking is
disabled on Switch 6 and Switch 7. Switch 8 has no power,
so the active topology includes switches: Switch 1, Switch 2,
Switch 3, and Switch 4.
Figure 2: Graphical Representation of Ring Topology
Figure 3: Summit X450e Series in a Ring Topology
Ring Topology
SummitStack nodes should be connected to each other in a
ring topology. In a ring topology, one link is used to connect
to a node and the other link is used to connect to another
node. The result forms a physical ring connection. This
topology is highly recommended for normal operation. Figure
2 shows a maximal ring topology of eight active nodes.
While a physical ring connection may be present, a ring
active topology only exists if all nodes in the stack are active
nodes. Figure 3 shows eight active Summit X450e series
switches in an ring topology.
Figure 1: Stack and Topologies
5333-01
s
s
s
s
s
s
s
s
Active
Topology
Stack
Topology
Stack
Switch 1
Switch 2
Switch 3
Switch 4
Failed Node
SummitStack™
Disabled
SummitStack
Disabled
No Power
Switch 5
Switch 6
Switch 7
Switch 8
5334-01