Default Stp Configuration; Stp Configuration Guidelines - Cisco Catalyst 2950 Software Configuration Manual

Configuring Spanning-Tree Features
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Default STP Configuration

Table 10-3
Table 10-3 Default STP Configuration
Feature
Enable state
Switch priority
Spanning-tree port priority (configurable on a per-interface basis—used on
interfaces configured as Layer 2 access ports)
Spanning-tree port cost (configurable on a per-interface basis—used on
interfaces configured as Layer 2 access ports)
Spanning-tree VLAN port priority (configurable on a per-VLAN basis—used on
interfaces configured as Layer 2 trunk ports)
Spanning-tree VLAN port cost (configurable on a per-VLAN basis—used on
interfaces configured as Layer 2 trunk ports)
Hello time
Forward-delay time
Maximum-aging time

STP Configuration Guidelines

If more VLANs are defined in the VTP than there are spanning-tree instances, you can enable STP on
only 64 VLANs. The remaining VLANs operate with spanning tree disabled. If the number of VLANs
exceeds 128, we recommend that you enable the MSTP to map multiple VLANs to a single spanning-tree
instance. For more information, see the
If 64 instances of spanning tree are already in use, you can disable STP on one of the VLANs and then
enable it on the VLAN where you want it to run. Use the no spanning-tree vlan vlan-id global
configuration command to disable STP on a specific VLAN, and use the spanning-tree vlan vlan-id
global configuration command to enable STP on the desired VLAN.
Catalyst 2950 Desktop Switch Software Configuration Guide
10-10
Configuring the Hello Time, page 10-18
Configuring the Forwarding-Delay Time for a VLAN, page 10-18
Configuring the Maximum-Aging Time for a VLAN, page 10-19
Configuring STP for Use in a Cascaded Stack, page 10-20
shows the default STP configuration.
Default Setting
Enabled on VLAN 1.
Up to 64 spanning-tree instances can be
enabled.
32768.
128.
1000 Mbps: 4.
100 Mbps: 19.
10 Mbps: 100.
128.
1000 Mbps: 4.
100 Mbps: 19.
10 Mbps: 100.
2 seconds.
15 seconds.
20 seconds.
Chapter 11, "Configuring RSTP and MSTP."
Chapter 10 Configuring STP
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