Cisco ASR 9000 Series

Configuring MSTP
This section describes the procedure for configuring MSTP:
This section does not describe how to configure data switching. Refer to the Implementing Multipoint Layer
2 Services module for more information.
Note
Enabling MSTP
By default, STP is disabled on all interfaces. MSTP should be explicitly enabled by configuration on each
physical or Ethernet Bundle interface. When MSTP is configured on an interface, all the subinterfaces of that
interface are automatically MSTP-enabled.
Configuring MSTP parameters
The MSTP Standard defines a number of configurable parameters. The global parameters are:
• Region Name and Revision
• Bringup Delay
• Forward Delay
• Max Age or Hops
• Transmit Hold Count
• Provider Bridge mode
• Flush Containment
• VLAN IDs (per spanning-tree instance)
• Bridge Priority (per spanning-tree instance)
The per-interface parameters are:
• External port path cost
• Hello Time
• Link Type
• Port Fast and BPDU Guard
• Root Guard and Topology Change Guard
• Port priority (per spanning-tree instance)
• Internal port path cost (per spanning-tree instance)
Per-interface configuration takes place in an interface submode within the MST configuration submode.
L2VPN and Ethernet Services Configuration Guide for Cisco ASR 9000 Series Routers, IOS XR Release 6.3.x
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Implementing Multiple Spanning Tree Protocol
Configuring MSTP