Administrator Guide

33 Dell Campus Networking Interoperability with Cisco Catalyst 1.1 | version 1.1
2.7.2 Configuring MST — Cisco Catalyst
In the following example, MST 0 is set to a priority of 4096. This insures that this switch will be the STP root
for instance 0. MST instance 0 is actually an Internal Spanning Tree (IST) and is limited to one per region.
Treat IST as a management STP instance and all non-assigned VLANs are placed in this instance by default.
The show spanning-tree mst 1, 2 command is then ran to show VLAN assignments and port
participation in the STP structure.
C6504#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
C6504(config)#spanning-tree mode mst
C6504(config)#spanning-tree mst 0 priority 4096
C6504(config)#spanning-tree mst configuration
C6504(config-mst)#name Region1
C6504(config-mst)#revision 1
C6504(config-mst)#instance 1 vlan 30-32
C6504(config-mst)#instance 2 vlan 33-35
C6504(config-mst)#end
C6504#show spanning-tree mst 1,2
##### MST1 vlans mapped: 30-32
Bridge address 68ef.bdea.b180 priority 32769 (32768 sysid 1)
Root address 001e.c9de.d11a priority 4097 (4096 sysid 1)
port Po5 cost 2000 rem hops 19
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po5 Root FWD 2000 128.1665 P2p
Po13 Altn BLK 2000 128.1666 P2p
##### MST2 vlans mapped: 33-35
Bridge address 68ef.bdea.b180 priority 32770 (32768 sysid 2)
Root address 001e.c9de.d142 priority 4098 (4096 sysid 2)
port Po13 cost 2000 rem hops 19
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Po5 Altn BLK 2000 128.1665 P2p
Po13 Root FWD 2000 128.1666 P2p