Cisco Systems 3550 Limitations, Connecting the Stack Ports

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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter10 Configuring STP
Understanding Advanced STP Features
Limitations
These limitations apply to CSUF:
•CSUF uses the GigaStack GBIC and runs on all Catalyst 3550 switches, all Catal yst 3500 XL
switches, but only on modular Catalyst 2900 XL switches that have th e 100 0BA SE -X m odu le
installed.
•Up to nine stack switches can be connected through their stack ports to the multidrop backbone.
Only one stack port per switch is supported.
•Each stack switch can be connected to the STP backbone thro ugh o ne up link.
•If the stack consists of a mixture of Catalyst 3550, Catalyst 3500 XL, and Catalyst 2900 XL
switches, up to 64 VLANs with STP enabled are supported. If the stack consists of
Catalyst 3550 s witches , up to 128 VLA Ns with STP enable d are suppor ted.
Connecting the Stack Ports
A fast transition occurs across the stack of switches if the multidrop backbone connections are a
continuous link from one GigaStack GBIC to another as shown in the top ha lf of Figur e 10-9. The
bottom half of Figure 10-9 shows how to connect the GigaStack GBIC to achiev e a no rmal conv er ge nce
time.
You should follow these guidelines:
•A switch supports only one stack port.
•Do not connect alternate stack-root ports to stack ports.
•Connect all stack ports on the switch stack to the multidrop backbone.
•You can connect the open ports on the top and bottom GigaStack GBICs within the same sta ck to
form a redundant link.