Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR
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Chapter 10 Configuring MSTP
Configuring MSTP Features
• Configuring the Forwarding-Delay Time, page 10-23 (optional)
• Configuring the Maximum-Aging Time, page 10-23 (optional)
• Configuring the Maximum-Hop Count, page 10-24 (optional)
• Specifying the Link Type to Ensure Rapid Transitions, page 10-24 (optional)
• Designating the Neighbor Type, page 10-25 (optional)
• Restarting the Protocol Migration Process, page 10-25 (optional)
Default MSTP Configuration
Table 10-4 shows the default MSTP configuration.
For information about the supported number of spanning-tree instances, see the “Supported
Spanning-Tree Instances” section on page 9-10.
MSTP Configuration Guidelines
• On the Cisco MWR 2941 router, MSTP is supported only on NNIs or ENIs on which STP has been
enabled. You enable STP on an ENI by entering the spanning-tree interface configuration
command. UNIs do not participate in 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.
• The router supports up to 65 MST instances. You can map up to 255 VLANs to a particular MST
instance.
Table 10-4 Default MSTP Configuration
Feature Default Setting
Spanning-tree mode PVST+
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.