Dell S4820T, Configuration Manual

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Creating Multiple Spanning Tree Instances
To create multiple spanning tree instances, use the following command.
A single MSTI provides no more benefit than RSTP. To take full advantage of MSTP, create multiple MSTIs
and map VLANs to them.
• Create an MSTI.
PROTOCOL MSTP mode
msti
Specify the keyword
vlan
then the VLANs that you want to participate in the MSTI.
Examples of Configuring and Viewing MSTI
The following examples shows the
msti
command.
Dell(conf)#protocol spanning-tree mstp
Dell(conf-mstp)# msti 1 vlan 100
Dell(conf-mstp)# msti 2 vlan 200-300
Dell(conf-mstp)#show config
!
protocol spanning-tree mstp
no disable
MSTI 1 VLAN 100
MSTI 2 VLAN 200-300
All bridges in the MSTP region must have the same VLAN-to-instance mapping.
To view which instance a VLAN is mapped to, use the
show spanning-tree mst vlan
command
from EXEC Privilege mode.
Dell(conf-mstp)#name my-mstp-region
Dell(conf-mstp)#exit
Dell(conf)#do show spanning-tree mst config
MST region name: my-mstp-region
Revision: 0
MSTI VID
1 100
2 200-300
To view the forwarding/discarding state of the ports participating in an MSTI, use the
show spanning-
tree msti
command from EXEC Privilege mode.
Dell#show spanning-tree msti 1
MSTI 1 VLANs mapped 100
Root Identifier has priority 32768, Address 0001.e806.953e
Root Bridge hello time 2, max age 20, forward delay 15, max hops 19
Bridge Identifier has priority 32768, Address 0001.e80d.b6d6
Configured hello time 2, max age 20, forward delay 15, max hops 20
Current root has priority 32768, Address 0001.e806.953e
Number of topology changes 2, last change occured 1d2h ago on Te 1/21
Port 374 (TenGigabitEthernet 1/21) is root Forwarding
Port path cost 20000, Port priority 128, Port Identifier 128.374
Designated root has priority 32768, address 0001.e806.953e
Designated bridge has priority 32768, address 0001.e806.953e
Multiple Spanning Tree Protocol (MSTP)
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