19-14
Cisco IE 3000 Switch Software Configuration Guide
OL-13018-03
Chapter 19 Configuring MSTP
Configuring MSTP Features
•
Configuring a Secondary Root Switch, page 19-18
(optional)
•
Configuring Port Priority, page 19-19
(optional)
•
Configuring Path Cost, page 19-20
(optional)
•
Configuring the Switch Priority, page 19-21
(optional)
•
Configuring the Hello Time, page 19-22
(optional)
•
Configuring the Forwarding-Delay Time, page 19-23
(optional)
•
Configuring the Maximum-Aging Time, page 19-23
(optional)
•
Configuring the Maximum-Hop Count, page 19-24
(optional)
•
Specifying the Link Type to Ensure Rapid Transitions, page 19-24
(optional)
•
Designating the Neighbor Type, page 19-25
(optional)
•
Restarting the Protocol Migration Process, page 19-25
(optional)
Default MSTP Configuration
Table 19-4
shows the default MSTP configuration.
For information about the supported number of spanning-tree instances, see the
“Supported
Spanning-Tree Instances” section on page 18-9
.
MSTP Configuration Guidelines
These are the configuration guidelines for MSTP:
•
When you enable MST by using the
spanning-tree mode mst
global configuration command, RSTP
is automatically enabled.
•
For two or more switches to be in the same MST region, they must have the same VLAN-to-instance
map, the same configuration revision number, and the same name.
Table 19-4
Default MSTP Configuration
Feature
Default Setting
Spanning-tree mode
PVST+ (Rapid PVST+ and MSTP are disabled).
Switch priority (configurable on a per-CIST port basis)
32768.
Spanning-tree port priority (configurable on a per-CIST port basis)
128.
Spanning-tree port cost (configurable on a per-CIST port basis)
1000 Mbps: 4.
100 Mbps: 19.
10 Mbps: 100.
Hello time
2 seconds.
Forward-delay time
15 seconds.
Maximum-aging time
20 seconds.
Maximum hop count
20 hops.