Configuring Stp And Uplinkfast In A Cascaded Cluster - Cisco WS-C2955T-12 Software Manual

Chapter 6 Configuring the System

Configuring STP and UplinkFast in a Cascaded Cluster

STP uses default values that can be reduced when configuring Catalyst 2900 XL and Catalyst 3500 XL
switches in cascaded configurations. If an STP root switch is part of a cluster that is one switch from a
cascaded stack, you can customize STP to reconverge more quickly after a switch failure.
shows modular Catalyst 2900 XL and Catalyst 3500 XL switches in three cascaded clusters that use the
GigaStack GBIC.
configurations.
Table 6-3
STP Parameter
Hello Time
Max Age
Forwarding delay
Figure 6-7
Catalyst
2900 and
3500 XL
switches
Enabling UplinkFast on all cluster switches can further reduce the time it takes cluster switches to begin
forwarding after a new root switch is selected.
78-6511-08
Table 6-3 shows the default STP settings and those that are acceptable for these
Default and Acceptable STP Parameter Settings (in Seconds)
STP Default
(IEEE)
2
20
15
Gigabit Ethernet Clusters
Catalyst
2900 and
3500 XL
switches
Option 1:
standalone
cascaded
cluster
Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide
Acceptable Acceptable
for Option 1 for Option 2
1 1
6 10
4 7
Catalyst 5000 series
switch
Catalyst
5000 series/
6000 backbone
Catalyst 6000
switch
Option 2:
cascaded
cluster connected to
a Layer 2 backbone
Configuring STP
Figure 6-7
Acceptable
for Option 3
1
6
4
Catalyst 2900
Cisco 7000
and 3500 XL
router
switches
Layer 3
backbone
Cisco 7000
router
Option 3:
cascaded
cluster connected to
a Layer 3 backbone
6-35