Default Stp Configuration; Enabling Stp - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Configuring STP
The STP commands described in this chapter can be configured on any LAN port, but they are in effect
Note
only on LAN ports configured with the switchport keyword.
We do not recommend disabling spanning tree, even in a topology that is free of physical loops. Spanning
Caution
tree serves as a safeguard against misconfigurations and cabling errors. Do not disable spanning tree in
a VLAN without ensuring that there are no physical loops present in the VLAN.

Default STP Configuration

Table 17-6
Table 17-6
Feature
Enable state
Bridge priority
STP port priority (configurable on a per-port
basis—used on LAN ports configured as
Layer 2 access ports)
STP port cost (configurable on a per-port
basis—used on LAN ports configured as
Layer 2 access ports)
STP VLAN port priority (configurable on a
per-VLAN basis—used on LAN ports
configured as Layer 2 trunk ports)
STP VLAN port cost (configurable on a
per-VLAN basis—used on LAN ports
configured as Layer 2 trunk ports)
Hello time
Forward delay time
Maximum aging time
Mode

Enabling STP

STP is enabled by default on VLAN 1 and on all newly created VLANs.
Note
You can enable STP on a per-VLAN basis. The Catalyst 6500 series switch maintains a separate instance
of STP for each VLAN (except on VLANs on which you disable STP).
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
17-26
shows the default STP configuration.
STP Default Configuration
Chapter 17
Default Value
STP enabled for all VLANs
32768
128
Gigabit Ethernet: 4
•
Fast Ethernet: 19
•
Ethernet: 100
•
128
Gigabit Ethernet: 4
•
Fast Ethernet: 19
•
Ethernet: 100
•
2 seconds
15 seconds
20 seconds
PVST
Configuring STP and MST
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