MSTP Configuration
This chapter contains a complete sample Multiple Spanning Tree Protocol (MSTP) configuration. MSTP allows multiple VLANs to be grouped into one spanning-tree instance. Every MST instance has a spanning-tree that is independent of other spanning-tree instances providing multiple forwarding paths for data traffic.
Topology
This example gives a simple multi-bridge topology and its configuration.
MSTP Topology
Note: Run the switchport command on each port to change to Layer-2 mode.
Configuration
Bridge 1
Bridge1#configure terminal | Enter configure mode. |
Bridge1(config)#bridge 1 protocol mstp | Add a bridge (1) to the multiple spanning tree table. |
Bridge1(config)#vlan database | Enter the VLAN configuration mode. |
Bridge1(config-vlan)#vlan 2 bridge 1 state enable | Enable the state of VLAN 2 on bridge 1. Specifying an enable state allows forwarding of frames over VLAN 2 on bridge 1. |
Bridge1(config-vlan)#vlan 3 bridge 1 state enable | Enable the state of VLAN 3 on bridge 1. Specifying an enable state allows forwarding of frames over VLAN 3 on bridge 1. |
Bridge1(config-vlan)#vlan 4 bridge 1 state enable | Enable the state of VLAN 4 on bridge 1. Specifying an enable state allows forwarding of frames over VLAN 4 on bridge 1. |
Bridge1(config-vlan)#vlan 5 bridge 1 state enable | Enable the state of VLAN 5 on bridge 1. Specifying an enable state allows forwarding of frames over VLAN 5 on bridge 1. |
Bridge1(config-vlan)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-vlan)#exit | Exit the VLAN configuration mode. |
Bridge1(config)#spanning-tree mst configuration | Enter the Multiple Spanning Tree |
Bridge1(config-mst)#bridge 1 instance 2 vlan 2 | Create an instance of VLAN. The VLANs must be created before being associating with an MST instance (MSTI). If the VLAN range is not specified the MSTI will not be created. |
Bridge1(config-mst)#bridge 1 instance 3 vlan 3 | Create another instance of VLAN. The VLANs must be created before being associating with an MST instance (MSTI). If the VLAN range is not specified the MSTI will not be created. |
Bridge1(config-mst)#bridge 1 instance 4 vlan 4 | same as mention above. |
Bridge1(config-mst)#bridge 1 instance 5 vlan 5 | same as mention above. |
Bridge1(config-mst)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-mst)#exit | Exit MST Configuration mode. |
Bridge1(config)#interface eth2 | Enter interface mode for eth2 |
Bridge1(config-if)#bridge-group 1 | Associating the interface to bridge-group 1 |
Bridge1(config-if)#bridge-group 1 instance 2 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 3 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 4 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 5 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-if)#exit | Exit interface mode. |
Bridge1(config)#interface eth3 | Enter interface mode for eth3. |
Bridge1(config-if)#bridge-group 1 | Associating the interface to bridge-group 1 |
Bridge1(config-if)#bridge-group 1 instance 2 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 3 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 4 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 5 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-if)#exit | Exit interface mode. |
Bridge1(config)#interface eth4 | Enter interface mode for eth4. |
Bridge1(config-if)#bridge-group 1 | Associating the interface to bridge-group 1 |
Bridge1(config-if)#bridge-group 1 instance 2 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 3 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 4 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 5 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-if)#exit | Exit interface mode. |
Bridge1(config)#interface eth5 | Enter interface mode for eth5. |
Bridge1(config-if)#bridge-group 1 | Associating the interface to bridge-group 1 |
Bridge1(config-if)#bridge-group 1 instance 2 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 3 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 4 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#bridge-group 1 instance 5 | Assigning bridge-group 1 to this instance |
Bridge1(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge1(config-if)#exit | Exit interface mode. |
Bridge 2
Bridge2#configure terminal | Enter configure mode. |
Bridge2(config)#bridge 2 protocol mstp | Add a bridge (2) to the multiple spanning |
Bridge2(config)#bridge 2 priority 4096 | Assign priority to this bridge. |
Bridge2(config)#vlan database | Enter the VLAN configuration mode. |
Bridge2(config-vlan)#vlan 2 bridge 2 state enable | Enable the state of VLAN 2 on bridge 2. Specifying an enable state allows forwarding of frames over VLAN 2 on bridge 2. |
Bridge2(config-vlan)#vlan 3 bridge 2 state enable | Enable the state of VLAN 3 on bridge 2. Specifying an enable state allows forwarding of frames over VLAN 3 on bridge 2 |
Bridge2(config-vlan)#vlan 4 bridge 2 state enable | Enable the state of VLAN 4 on bridge 2. Specifying an enable state allows forwarding of frames over VLAN 4 on bridge 2 |
Bridge2(config-vlan)#vlan 5 bridge 2 state enable | Enable the state of VLAN 5 on bridge 2. Specifying an enable state allows forwarding of frames over VLAN 5 on bridge 2 |
Bridge2(config-vlan)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-vlan)#exit | Exit the VLAN configuration mode. |
Bridge2(config)#spanning-tree mst configuration | Enter the Multiple Spanning Tree configuration mode |
Bridge2(config-mst)#bridge 2 instance 2 vlan 2 | Create an instance of VLAN. The VLANs must be created before being associating with an MST instance (MSTI). If the VLAN range is not specified the MSTI will not be created. |
Bridge2(config-mst)#bridge 2 instance 3 vlan 3 | same as mention above. |
Bridge2(config-mst)#bridge 2 instance 4 vlan 4 | same as mention above. |
Bridge2(config-mst)#bridge 2 instance 5 vlan 5 | same as mention above. |
Bridge2(config-mst)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-mst)#exit | Exit MST Configuration mode. |
Bridge2(config)#interface eth2 | Enter interface mode for eth2 |
Bridge2(config-if)#bridge-group 2 | Associating the interface to bridge-group 2 |
Bridge2(config-if)#bridge-group 2 instance 2 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 3 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 4 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 5 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-if)#exit | Exit interface mode. |
Bridge2(config)#interface eth3 | Enter interface mode for eth3 |
Bridge2(config-if)#bridge-group 2 | Associating the interface to bridge-group 2 |
Bridge2(config-if)#bridge-group 2 instance 2 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 3 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 3 priority 16 | Assign bridge-group 2 to this instance and set a port priority in order of 16 for it. MSTP uses port priority as a tiebreaker to determine which port should forward frames for a particular instance on a LAN, or which port should be the root port for an instance. A lower value implies better priority. |
Bridge2(config-if)#bridge-group 2 instance 4 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 4 priority 16 | Assign bridge-group 2 to this instance and set a port priority in order of 16 for it. MSTP uses port priority as a tiebreaker to determine which port should forward frames for a particular instance on a LAN, or which port should be the root port for an instance. A lower value implies better priority |
Bridge2(config-if)#bridge-group 2 instance 5 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-if)#exit | Exit interface mode |
Bridge2(config)#interface eth4 | Enter interface mode for eth4 |
Bridge2(config-if)#bridge-group 2 | Associating the interface to bridge-group 2 |
Bridge2(config-if)#bridge-group 2 instance 2 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 3 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 4 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 5 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-if)#exit | Exit interface mode. |
Bridge2(config)#interface eth5 | Enter interface mode for eth5 |
Bridge2(config-if)#bridge-group 2 | Associating the interface to bridge-group 2 |
Bridge2(config-if)#bridge-group 2 instance 2 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 3 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 4 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#bridge-group 2 instance 5 | Assigning bridge-group 2 to this instance |
Bridge2(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge2(config-if)#exit | Exit interface mode. |
Bridge 3
Bridge3#configure terminal | Enter configure mode. |
Bridge3(config)#bridge 3 protocol mstp | Add a bridge (3) to the multiple spanning tree table |
Bridge3(config)#vlan database | Enter the VLAN configuration mode. |
Bridge3(config-vlan)#vlan 2 bridge 3 state enable | Enable the state of VLAN 2 on bridge 3. Specifying an enable state allows forwarding of frames over VLAN 2 on bridge 3. |
Bridge3(config-vlan)#vlan 3 bridge 3 state enable | Enable the state of VLAN 3 on bridge 3. Specifying an enable state allows forwarding of frames over VLAN 3 on bridge 3. |
Bridge3(config-vlan)#vlan 4 bridge 3 state enable | Enable the state of VLAN 4 on bridge 3. Specifying an enable state allows forwarding of frames over VLAN 4 on bridge 3. |
Bridge3(config-vlan)#vlan 5 bridge 3 state enable | Enable the state of VLAN 5 on bridge 3. Specifying an enable state allows forwarding of frames over VLAN 5 on bridge 3. |
Bridge3(config-vlan)#commit | Commit candidate configuration to be running configuration |
Bridge3(config-vlan)#exit | Exit the VLAN configuration mode. |
Bridge3(config)#spanning-tree mst configuration | Enter the Multiple Spanning Tree Configuration mode. |
Bridge3(config-mst)#bridge 3 instance 2 vlan 2 | Create an instance of VLAN. The VLANs must be created before being associating with an MST instance (MSTI). If the VLAN range is not specified the MSTI will not be created. |
Bridge3(config-mst)#bridge 3 instance 3 vlan 3 | same as mention above. |
Bridge3(config-mst)#bridge 3 instance 4 vlan 4 | same as mention above. |
Bridge3(config-mst)#bridge 3 instance 5 vlan 5 | same as mention above. |
Bridge3(config-mst)#commit | Commit candidate configuration to be running configuration |
Bridge3(config-mst)#exit | Exit MST Configuration mode. |
Bridge3(config)#interface eth2 | Enter interface mode for eth2 |
Bridge3(config-if)#bridge-group 3 | Associating the interface to bridge-group 3 |
Bridge3(config-if)#bridge-group 3 instance 2 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 3 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 4 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 5 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge3(config-if)#exit | Exit interface mode. |
Bridge3(config)#interface eth3 | Enter interface mode for eth3 |
Bridge3(config-if)#bridge-group 3 | Associating the interface to bridge-group 3 |
Bridge3(config-if)#bridge-group 3 instance 2 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 3 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 4 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#bridge-group 3 instance 5 | Assigning bridge-group 3 to this instance |
Bridge3(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge3(config-if)#exit | Exit interface mode. |
Bridge 4
Bridge4#configure terminal | Enter configure mode. |
Bridge4(config)#bridge 4 protocol mstp | Add a bridge (4) to the multiple spanning tree table |
Bridge4(config)#vlan database | Enter the VLAN configuration mode. |
Bridge4(config-vlan)#vlan 2 bridge 4 state enable | Enable the state of VLAN 2 on bridge 4. Specifying an enable state allows forwarding of frames over VLAN 2 on bridge 4. |
Bridge4(config-vlan)#vlan 3 bridge 4 state enable | Enable the state of VLAN 3 on bridge 4. Specifying an enable state allows forwarding of frames over VLAN 3 on bridge 4. |
Bridge4(config-vlan)#vlan 4 bridge 4 state enable | Enable the state of VLAN 4 on bridge 4. Specifying an enable state allows forwarding of frames over VLAN 4 on bridge 4. |
Bridge4(config-vlan)#vlan 5 bridge 4 state enable | Enable the state of VLAN 5 on bridge 4. Specifying an enable state allows forwarding of frames over VLAN 5 on bridge 4. |
Bridge4(config-vlan)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-vlan)#exit | Exit the VLAN configuration mode. |
Bridge4(config)#spanning-tree mst configuration | Enter the Multiple Spanning Tree Configuration mode. |
Bridge4(config-mst)#bridge 4 instance 2 vlan 2 | Create an instance of VLAN. The VLANs must be created before being associating with an MST instance (MSTI). If the VLAN range is not specified the MSTI will not be created. |
Bridge4(config-mst)#bridge 4 instance 3 vlan 3 | same as mention above. |
Bridge4(config-mst)#bridge 4 instance 4 vlan 4 | same as mention above. |
Bridge4(config-mst)#bridge 4 instance 5 vlan 5 | same as mention above. |
Bridge4(config-mst)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-mst)#exit | Exit MST Configuration mode. |
Bridge4(config)#interface eth2 | Enter interface mode for eth2 |
Bridge4(config-if)#bridge-group 4 | Associating the interface to bridge-group 4 |
Bridge4(config-if)#bridge-group 4 instance 2 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 3 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 4 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 5 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-if)#exit | Exit interface mode. |
Bridge4(config)#interface eth3 | Enter interface mode for eth3 |
Bridge4(config-if)#bridge-group 4 | Associating the interface to bridge-group 4 |
Bridge4(config-if)#bridge-group 4 instance 2 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 3 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 4 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 5 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-if)#exit | Exit interface mode. |
Bridge4(config)#interface eth4 | Enter interface mode for eth4 |
Bridge4(config-if)#bridge-group 4 | Associating the interface to bridge-group 4 |
Bridge4(config-if)#bridge-group 4 instance 2 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 3 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 4 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 5 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-if)#exit | Exit interface mode. |
Bridge4(config)#interface eth5 | Enter interface mode for eth5 |
Bridge4(config-if)#bridge-group 4 | Associating the interface to bridge-group 4 |
Bridge4(config-if)#bridge-group 4 instance 2 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 3 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 4 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#bridge-group 4 instance 5 | Assigning bridge-group 4 to this instance |
Bridge4(config-if)#commit | Commit candidate configuration to be running configuration |
Bridge4(config-if)#exit | Exit interface mode. |
Validation
show spanning-tree, show spanning-tree mst detail
#show spanning-tree mst detail
% 1: Bridge up - Spanning Tree Enabled - topology change detected
% 1: CIST Root Path Cost 0 - CIST Root Port 3 - CIST Bridge Priority 32768
% 1: Forward Delay 15 - Hello Time 2 - Max Age 20 - Transmit Hold Count 6 - Max-hops 20
% 1: CIST Root Id 1000525400d15789
% 1: CIST Reg Root Id 1000525400d15789
% 1: CIST Bridge Id 8000525400244323
% 1: 26 topology change(s) - last topology change Mon Mar 4 12:58:35 2019
% 1: portfast bpdu-filter disabled
% 1: portfast bpdu-guard disabled
% 1: portfast errdisable timeout disabled
% 1: portfast errdisable timeout interval 300 sec
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Rootport - State Forwarding
% eth1: Designated External Path Cost 0 -Internal Path Cost 20000
% eth1: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth1: Designated Port Id 0x8003 - CIST Priority 128 -
% eth1: CIST Root 1000525400d15789
% eth1: Regional Root 1000525400d15789
% eth1: Designated Bridge 1000525400d15789
% eth1: Message Age 0 - Max Age 20
% eth1: CIST Hello Time 2 - Forward Delay 15
% eth1: CIST Forward Timer 0 - Msg Age Timer 5 - Hello Timer 0 - topo change timer 0
% eth1: forward-transitions 1
% eth1: Version Multiple Spanning Tree Protocol - Received MSTP - Send MSTP
% eth1: No portfast configured - Current portfast off
% eth1: bpdu-guard default - Current bpdu-guard off
% eth1: bpdu-filter default - Current bpdu-filter off
% eth1: no root guard configured - Current root guard off
% eth1: Configured Link Type point-to-point - Current point-to-point
% eth1: No auto-edge configured - Current port Auto Edge off
%
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Alternate - State Discarding
% eth2: Designated External Path Cost 0 -Internal Path Cost 20000
% eth2: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth2: Designated Port Id 0x8004 - CIST Priority 128 -
% eth2: CIST Root 1000525400d15789
% eth2: Regional Root 1000525400d15789
% eth2: Designated Bridge 1000525400d15789
% eth2: Message Age 0 - Max Age 20
% eth2: CIST Hello Time 2 - Forward Delay 15
% eth2: CIST Forward Timer 0 - Msg Age Timer 5 - Hello Timer 1 - topo change timer 0
% eth2: forward-transitions 2
% eth2: Version Multiple Spanning Tree Protocol - Received MSTP - Send MSTP
% eth2: No portfast configured - Current portfast off
% eth2: bpdu-guard default - Current bpdu-guard off
% eth2: bpdu-filter default - Current bpdu-filter off
% eth2: no root guard configured - Current root guard off
% eth2: Configured Link Type point-to-point - Current point-to-point
% eth2: No auto-edge configured - Current port Auto Edge off
%
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated External Path Cost 0 -Internal Path Cost 20000
% eth3: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth3: Designated Port Id 0x8005 - CIST Priority 128 -
% eth3: CIST Root 1000525400d15789
% eth3: Regional Root 1000525400d15789
% eth3: Designated Bridge 8000525400244323
% eth3: Message Age 0 - Max Age 20
% eth3: CIST Hello Time 2 - Forward Delay 15
% eth3: CIST Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1 - topo change timer 0
% eth3: forward-transitions 3
% eth3: Version Multiple Spanning Tree Protocol - Received None - Send MSTP
% eth3: No portfast configured - Current portfast off
% eth3: bpdu-guard default - Current bpdu-guard off
% eth3: bpdu-filter default - Current bpdu-filter off
% eth3: no root guard configured - Current root guard off
% eth3: Configured Link Type point-to-point - Current point-to-point
% eth3: No auto-edge configured - Current port Auto Edge off
%
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated External Path Cost 0 -Internal Path Cost 20000
% eth4: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth4: Designated Port Id 0x8006 - CIST Priority 128 -
% eth4: CIST Root 1000525400d15789
% eth4: Regional Root 1000525400d15789
% eth4: Designated Bridge 8000525400244323
% eth4: Message Age 0 - Max Age 20
% eth4: CIST Hello Time 2 - Forward Delay 15
% eth4: CIST Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1 - topo change timer 0
% eth4: forward-transitions 3
% eth4: Version Multiple Spanning Tree Protocol - Received None - Send MSTP
% eth4: No portfast configured - Current portfast off
% eth4: bpdu-guard default - Current bpdu-guard off
% eth4: bpdu-filter default - Current bpdu-filter off
% eth4: no root guard configured - Current root guard off
% eth4: Configured Link Type point-to-point - Current point-to-point
% eth4: No auto-edge configured - Current port Auto Edge off
%
% Instance 2: Vlans: 2
% 1: MSTI Root Path Cost 0 -MSTI Root Port 0 - MSTI Bridge Priority 32768
% 1: MSTI Root Id 8002525400244323
% 1: MSTI Bridge Id 8002525400244323
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Designated - State Forwarding
% eth1: Designated Internal Path Cost 0 - Designated Port Id 0x8003
% eth1: Configured Internal Path Cost 20000
% eth1: Configured CST External Path cost 20000
% eth1: CST Priority 128 - MSTI Priority 128
% eth1: Designated Root 8002525400244323
% eth1: Designated Bridge 8002525400244323
% eth1: Message Age 0
% eth1: Hello Time 2 - Forward Delay 15
% eth1: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 0
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Designated - State Forwarding
% eth2: Designated Internal Path Cost 0 - Designated Port Id 0x8004
% eth2: Configured Internal Path Cost 20000
% eth2: Configured CST External Path cost 20000
% eth2: CST Priority 128 - MSTI Priority 128
% eth2: Designated Root 8002525400244323
% eth2: Designated Bridge 8002525400244323
% eth2: Message Age 0
% eth2: Hello Time 2 - Forward Delay 15
% eth2: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated Internal Path Cost 0 - Designated Port Id 0x8005
% eth3: Configured Internal Path Cost 20000
% eth3: Configured CST External Path cost 20000
% eth3: CST Priority 128 - MSTI Priority 128
% eth3: Designated Root 8002525400244323
% eth3: Designated Bridge 8002525400244323
% eth3: Message Age 0
% eth3: Hello Time 2 - Forward Delay 15
% eth3: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated Internal Path Cost 0 - Designated Port Id 0x8006
% eth4: Configured Internal Path Cost 20000
% eth4: Configured CST External Path cost 20000
% eth4: CST Priority 128 - MSTI Priority 128
% eth4: Designated Root 8002525400244323
% eth4: Designated Bridge 8002525400244323
% eth4: Message Age 0
% eth4: Hello Time 2 - Forward Delay 15
% eth4: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% Instance 3: Vlans: 3
% 1: MSTI Root Path Cost 0 -MSTI Root Port 0 - MSTI Bridge Priority 32768
% 1: MSTI Root Id 8003525400244323
% 1: MSTI Bridge Id 8003525400244323
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Masterport - State Forwarding
% eth1: Designated Internal Path Cost 0 - Designated Port Id 0x8003
% eth1: Configured Internal Path Cost 20000
% eth1: Configured CST External Path cost 20000
% eth1: CST Priority 128 - MSTI Priority 128
% eth1: Designated Root 8003525400244323
% eth1: Designated Bridge 8003525400244323
% eth1: Message Age 0
% eth1: Hello Time 2 - Forward Delay 15
% eth1: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 0
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Designated - State Forwarding
% eth2: Designated Internal Path Cost 0 - Designated Port Id 0x8004
% eth2: Configured Internal Path Cost 20000
% eth2: Configured CST External Path cost 20000
% eth2: CST Priority 128 - MSTI Priority 128
% eth2: Designated Root 8003525400244323
% eth2: Designated Bridge 8003525400244323
% eth2: Message Age 0
% eth2: Hello Time 2 - Forward Delay 15
% eth2: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated Internal Path Cost 0 - Designated Port Id 0x8005
% eth3: Configured Internal Path Cost 20000
% eth3: Configured CST External Path cost 20000
% eth3: CST Priority 128 - MSTI Priority 128
% eth3: Designated Root 8003525400244323
% eth3: Designated Bridge 8003525400244323
% eth3: Message Age 0
% eth3: Hello Time 2 - Forward Delay 15
% eth3: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated Internal Path Cost 0 - Designated Port Id 0x8006
% eth4: Configured Internal Path Cost 20000
% eth4: Configured CST External Path cost 20000
% eth4: CST Priority 128 - MSTI Priority 128
% eth4: Designated Root 8003525400244323
% eth4: Designated Bridge 8003525400244323
% eth4: Message Age 0
% eth4: Hello Time 2 - Forward Delay 15
% eth4: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% Instance 4: Vlans: 4
% 1: MSTI Root Path Cost 0 -MSTI Root Port 0 - MSTI Bridge Priority 32768
% 1: MSTI Root Id 8004525400244323
% 1: MSTI Bridge Id 8004525400244323
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Masterport - State Forwarding
% eth1: Designated Internal Path Cost 0 - Designated Port Id 0x8003
% eth1: Configured Internal Path Cost 20000
% eth1: Configured CST External Path cost 20000
% eth1: CST Priority 128 - MSTI Priority 128
% eth1: Designated Root 8004525400244323
% eth1: Designated Bridge 8004525400244323
% eth1: Message Age 0
% eth1: Hello Time 2 - Forward Delay 15
% eth1: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 0
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Designated - State Forwarding
% eth2: Designated Internal Path Cost 0 - Designated Port Id 0x8004
% eth2: Configured Internal Path Cost 20000
% eth2: Configured CST External Path cost 20000
% eth2: CST Priority 128 - MSTI Priority 128
% eth2: Designated Root 8004525400244323
% eth2: Designated Bridge 8004525400244323
% eth2: Message Age 0
% eth2: Hello Time 2 - Forward Delay 15
% eth2: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated Internal Path Cost 0 - Designated Port Id 0x8005
% eth3: Configured Internal Path Cost 20000
% eth3: Configured CST External Path cost 20000
% eth3: CST Priority 128 - MSTI Priority 128
% eth3: Designated Root 8004525400244323
% eth3: Designated Bridge 8004525400244323
% eth3: Message Age 0
% eth3: Hello Time 2 - Forward Delay 15
% eth3: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated Internal Path Cost 0 - Designated Port Id 0x8006
% eth4: Configured Internal Path Cost 20000
% eth4: Configured CST External Path cost 20000
% eth4: CST Priority 128 - MSTI Priority 128
% eth4: Designated Root 8004525400244323
% eth4: Designated Bridge 8004525400244323
% eth4: Message Age 0
% eth4: Hello Time 2 - Forward Delay 15
% eth4: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% Instance 5: Vlans: 5
% 1: MSTI Root Path Cost 0 -MSTI Root Port 0 - MSTI Bridge Priority 32768
% 1: MSTI Root Id 8005525400244323
% 1: MSTI Bridge Id 8005525400244323
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Masterport - State Forwarding
% eth1: Designated Internal Path Cost 0 - Designated Port Id 0x8003
% eth1: Configured Internal Path Cost 20000
% eth1: Configured CST External Path cost 20000
% eth1: CST Priority 128 - MSTI Priority 128
% eth1: Designated Root 8005525400244323
% eth1: Designated Bridge 8005525400244323
% eth1: Message Age 0
% eth1: Hello Time 2 - Forward Delay 15
% eth1: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 0
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Designated - State Forwarding
% eth2: Designated Internal Path Cost 0 - Designated Port Id 0x8004
% eth2: Configured Internal Path Cost 20000
% eth2: Configured CST External Path cost 20000
% eth2: CST Priority 128 - MSTI Priority 128
% eth2: Designated Root 8005525400244323
% eth2: Designated Bridge 8005525400244323
% eth2: Message Age 0
% eth2: Hello Time 2 - Forward Delay 15
% eth2: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated Internal Path Cost 0 - Designated Port Id 0x8005
% eth3: Configured Internal Path Cost 20000
% eth3: Configured CST External Path cost 20000
% eth3: CST Priority 128 - MSTI Priority 128
% eth3: Designated Root 8005525400244323
% eth3: Designated Bridge 8005525400244323
% eth3: Message Age 0
% eth3: Hello Time 2 - Forward Delay 15
% eth3: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated Internal Path Cost 0 - Designated Port Id 0x8006
% eth4: Configured Internal Path Cost 20000
% eth4: Configured CST External Path cost 20000
% eth4: CST Priority 128 - MSTI Priority 128
% eth4: Designated Root 8005525400244323
% eth4: Designated Bridge 8005525400244323
% eth4: Message Age 0
% eth4: Hello Time 2 - Forward Delay 15
% eth4: Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1
#show spanning-tree
% 1: Bridge up - Spanning Tree Enabled - topology change detected
% 1: CIST Root Path Cost 0 - CIST Root Port 3 - CIST Bridge Priority 32768
% 1: Forward Delay 15 - Hello Time 2 - Max Age 20 - Transmit Hold Count 6 - Max-hops 20
% 1: CIST Root Id 1000525400d15789
% 1: CIST Reg Root Id 1000525400d15789
% 1: CIST Bridge Id 8000525400244323
% 1: 26 topology change(s) - last topology change Mon Mar 4 12:58:35 2019
% 1: portfast bpdu-filter disabled
% 1: portfast bpdu-guard disabled
% 1: portfast errdisable timeout disabled
% 1: portfast errdisable timeout interval 300 sec
% eth1: Port Number 3 - Ifindex 3 - Port Id 0x8003 - Role Rootport - State Forwarding
% eth1: Designated External Path Cost 0 -Internal Path Cost 20000
% eth1: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth1: Designated Port Id 0x8003 - CIST Priority 128 -
% eth1: CIST Root 1000525400d15789
% eth1: Regional Root 1000525400d15789
% eth1: Designated Bridge 1000525400d15789
% eth1: Message Age 0 - Max Age 20
% eth1: CIST Hello Time 2 - Forward Delay 15
% eth1: CIST Forward Timer 0 - Msg Age Timer 5 - Hello Timer 1 - topo change timer 0
% eth1: forward-transitions 1
% eth1: Version Multiple Spanning Tree Protocol - Received MSTP - Send MSTP
% eth1: No portfast configured - Current portfast off
% eth1: bpdu-guard default - Current bpdu-guard off
% eth1: bpdu-filter default - Current bpdu-filter off
% eth1: no root guard configured - Current root guard off
% eth1: Configured Link Type point-to-point - Current point-to-point
% eth1: No auto-edge configured - Current port Auto Edge off
%
% eth2: Port Number 4 - Ifindex 4 - Port Id 0x8004 - Role Alternate - State Discarding
% eth2: Designated External Path Cost 0 -Internal Path Cost 20000
% eth2: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth2: Designated Port Id 0x8004 - CIST Priority 128 -
% eth2: CIST Root 1000525400d15789
% eth2: Regional Root 1000525400d15789
% eth2: Designated Bridge 1000525400d15789
% eth2: Message Age 0 - Max Age 20
% eth2: CIST Hello Time 2 - Forward Delay 15
% eth2: CIST Forward Timer 0 - Msg Age Timer 5 - Hello Timer 0 - topo change timer 0
% eth2: forward-transitions 2
% eth2: Version Multiple Spanning Tree Protocol - Received MSTP - Send MSTP
% eth2: No portfast configured - Current portfast off
% eth2: bpdu-guard default - Current bpdu-guard off
% eth2: bpdu-filter default - Current bpdu-filter off
% eth2: no root guard configured - Current root guard off
% eth2: Configured Link Type point-to-point - Current point-to-point
% eth2: No auto-edge configured - Current port Auto Edge off
%
% eth3: Port Number 5 - Ifindex 5 - Port Id 0x8005 - Role Designated - State Forwarding
% eth3: Designated External Path Cost 0 -Internal Path Cost 20000
% eth3: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth3: Designated Port Id 0x8005 - CIST Priority 128 -
% eth3: CIST Root 1000525400d15789
% eth3: Regional Root 1000525400d15789
% eth3: Designated Bridge 8000525400244323
% eth3: Message Age 0 - Max Age 20
% eth3: CIST Hello Time 2 - Forward Delay 15
% eth3: CIST Forward Timer 0 - Msg Age Timer 0 - Hello Timer 1 - topo change timer 0
% eth3: forward-transitions 3
% eth3: Version Multiple Spanning Tree Protocol - Received None - Send MSTP
% eth3: No portfast configured - Current portfast off
% eth3: bpdu-guard default - Current bpdu-guard off
% eth3: bpdu-filter default - Current bpdu-filter off
% eth3: no root guard configured - Current root guard off
% eth3: Configured Link Type point-to-point - Current point-to-point
% eth3: No auto-edge configured - Current port Auto Edge off
%
% eth4: Port Number 6 - Ifindex 6 - Port Id 0x8006 - Role Designated - State Forwarding
% eth4: Designated External Path Cost 0 -Internal Path Cost 20000
% eth4: Configured Path Cost 20000 - Add type Explicit ref count 5
% eth4: Designated Port Id 0x8006 - CIST Priority 128 -
% eth4: CIST Root 1000525400d15789
% eth4: Regional Root 1000525400d15789
% eth4: Designated Bridge 8000525400244323
% eth4: Message Age 0 - Max Age 20
% eth4: CIST Hello Time 2 - Forward Delay 15
% eth4: CIST Forward Timer 0 - Msg Age Timer 0 - Hello Timer 0 - topo change timer 0
% eth4: forward-transitions 3
% eth4: Version Multiple Spanning Tree Protocol - Received None - Send MSTP
% eth4: No portfast configured - Current portfast off
% eth4: bpdu-guard default - Current bpdu-guard off
% eth4: bpdu-filter default - Current bpdu-filter off
% eth4: no root guard configured - Current root guard off
% eth4: Configured Link Type point-to-point - Current point-to-point
% eth4: No auto-edge configured - Current port Auto Edge off%
#