Enterasys C5G124-24 Configuration Manual page 247

displayed in the following example. By default, every bridge will have a FID-to-SID mapping that
equals VLAN FID 1/SID 0.
Use the show spantree mstcfgid command to determine MSTI configuration identifier
information, and whether or not there is a misconfiguration due to non-matching configuration
identifier components:
This example shows how to display MSTI configuration identifier information. In this case, this
bridge belongs to "Region1":
Enterasys->show spantree mstcfgid
MST Configuration Identifier:
Format Selector:
Configuration Name:
Revision Level:
Configuration Digest: 6d:d7:93:10:91:c9:69:ff:48:f2:ef:bf:cd:8b:cc:de
In order for other bridges to belong to Region1, all four elements of those bridges' configuration id
output must match. The default value that must be changed for this to happen is the configuration
name setting. Also, the MSTIs must be created and the FIDs mapped to them.
Use the set spantree mstcfgid command to change the configuration name from the default
bridge MAC address value.
This example changes the default bridge configuration name to Region1:
Enterasys->set spantree mstcfgid cfgname Region1
For the configuration digest to match, the mapping of VIDs to SIDs must match. Use these
commands to configure the SIDs, map the FIDs to the SIDs and display the VID-SID and FID-SID
mappings:
Enterasys->set spantree msti sid 3 create
Enterasys->set spantree msti sid 4 create
Enterasys->set spantree mstmap 3 sid 3
Enterasys->set spantree mstmap 4 sid 4
Enterasys->show spantree mstilist
Configured Multiple Spanning Tree Instances:
3 4
Enterasys->show spantree mstmap
Fid 3 is mapped to Sid 3
Fid 4 is mapped to Sid 4
Enterasys->show spantree vlanlist
Vlan 3 is mapped to Sid 3
Vlan 4 is mapped to Sid 4
Since an MSTI is a separate Spanning Tree, each MSTI has its own root inside the MST region.
Figure 15-8 on page 15-18 and
Switching device 3 is the root for MSTI 1, switching device 2 is the root for MSTI 2, and switching
device 5 is the CIST regional root. Traffic for all the VLANs attached to an MSTI follow the MSTI's
spanned topology.
Various options may be configured on a per-MSTI basis to allow for differing topologies between
MSTIs. To reduce network complexity and processing overhead needed to maintain MSTIs, you
should only create as many MSTIs as needed.
0
Region1
88
Figure 15-9 on page 15-18 show two MSTIs in a single region.
Spanning Tree Basics
Fixed Switch Configuration Guide 15-17