Cisco WS-C2950-24 Configuration Manual page 168

Configuring STP
Figure 6-7 Cross-Stack UplinkFast Topology
Spanning
tree root
Fwd
Link A
(Root link)
100 or 1000 Mbps
Stack root port
Switch A
Stack port
Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
6-32
Backbone
Fwd
Fwd
Switch B Stack port
Multidrop backbone
(GigaStack GBIC connections)
CSUF implements the Stack Membership Discovery Protocol and the Fast Uplink
Transition Protocol. Using the Stack Membership Discovery Protocol, all stack
switches build a neighbor list of stack members through the receipt of discovery
hello packets. When certain link loss or STP events occur (described in the
"Events that Cause Fast Convergence" section on page
Transition Protocol uses the neighbor list to send fast-transition requests on the
stack port to stack members.
Link B
(Alternate
redundant
link)
100 or 1000 Mbps
Alternate stack
root port
Chapter 6 Configuring the System
Link C
(Alternate
redundant
link)
100 or 1000 Mbps
Alternate stack
root port
Switch C Stack port
6-33), the Fast Uplink
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