Before you execute the following instructions, ensure that all of the switches are in their default configuration. Also, disable GVRP, and start and enable PVRST+ on all switches. In the default configuration, vlan 1 is the default VLAN. If you plan to use another VLAN ID as the default VLAN, you must configure and enable the VLAN ID.
In the following examples, ports are configured as trunk, and vlan 10 is enabled on all three switches. vlan 10 is also used to show spanning tree status on switch C. See VLAN Module for information about configuring the VLAN module.
After the topology stabilizes, switch A is elected as the root because it has the lowest MAC address. All ports on all switches, except port 57 on switch C, should be in forwarding state. Port 57 on switch C should be detected as an alternate port in the discarding state.
Complete the following task on all three switches before setting the priority on switch C for the STP. Note that the following examples are run on switch C and similar commands must be run on switches A and B as well.
SEFOS-2 SEFOS# configure terminal SEFOS-2 SEFOS(config)#
SEFOS-2 SEFOS(config)# set gvrp disable SEFOS-2 SEFOS(config)#
SEFOS-2 SEFOS(config)# vlan 10 SEFOS-2 SEFOS(config-vlan)# vlan active SEFOS-2 SEFOS(config-vlan)# exit SEFOS-2 SEFOS(config)#
SEFOS-2 SEFOS(config)# interface extreme-ethernet 0/1 SEFOS-2 SEFOS(config-if)# switchport mode trunk SEFOS-2 SEFOS(config-if)# no shutdown SEFOS-2 SEFOS(config-if)# exit SEFOS-2 SEFOS(config)# SEFOS-2 SEFOS(config)# interface extreme-ethernet 0/57 SEFOS-2 SEFOS(config-if)# switchport mode trunk SEFOS-2 SEFOS(config-if)# no shutdown SEFOS-2 SEFOS(config-if)# exit SEFOS-2 SEFOS(config)#
SEFOS-2 SEFOS(config)# interface vlan 10 SEFOS-2 SEFOS(config-if)# shutdown SEFOS-2 SEFOS(config-if)# ip address 192.168.10.149 255.255.255.0 SEFOS-2 SEFOS(config-if)# no shutdown SEFOS-2 SEFOS(config-if)# end SEFOS-2 SEFOS#
Port 57 should be in discarding state.
SEFOS-2 SEFOS# show spanning-tree vlan 10 ----------------------------------------------------------------- Spanning-tree for VLAN 10 Root Id Priority 32778 Address 00:14:4f:6c:56:6f Cost 2000 Port Ex0/1 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32778 Address 00:14:4f:6c:6e:0d Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/1 Root Forwarding 2000 128 P2P Ex0/57 Alternate Discarding 2000 128 P2P SEFOS-2 SEFOS#
SEFOS-2 SEFOS# ping 192.168.10.199 Reply Received From :192.168.10.199, TimeTaken : 160 msecs Reply Received From :192.168.10.199, TimeTaken : 110 msecs Reply Received From :192.168.10.199, TimeTaken : 90 msecs --- 192.168.10.199 Ping Statistics --- 3 Packets Transmitted, 3 Packets Received, 0% Packets Loss SEFOS-2 SEFOS# SEFOS-2 SEFOS# ping 192.168.10.144 Reply Received From :192.168.10.144, TimeTaken : 100 msecs Reply Received From :192.168.10.144, TimeTaken : 100 msecs Reply Received From :192.168.10.144, TimeTaken : 110 msecs --- 192.168.10.144 Ping Statistics --- 3 Packets Transmitted, 3 Packets Received, 0% Packets Loss SEFOS-2 SEFOS#
SEFOS-2 SEFOS# configure terminal SEFOS-2 SEFOS(config)# spanning-tree vlan 10 brg-priority 4096 SEFOS-2 SEFOS(config)# end SEFOS-2 SEFOS#
In the PVRST+ software, the spanning-tree parameters apply only to the specified VLAN.
For brg-priority, you can provide a value from 0 to 61440 in increments of 4096. The priority you provide is combined with the VLAN ID to obtain the actual priority for the instance created for the VLAN. If you do not specify a value, the VLAN ID is combined with a default value of 32768. If the combined number is lower than the other switches, the more likely it is that the switch will be chosen as the root switch.
Valid priority values are: 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440.
NEM-1 SEFOS# show spanning-tree vlan 10 ------------------------------------------------------------------- Spanning-tree for VLAN 10 Root Id Priority 4106 Address 00:14:4f:6c:6e:0d Cost 2000 Port Ex0/7 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32778 Address 00:14:4f:6c:56:6f Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/3 Designated Forwarding 2000 128 P2P Ex0/7 Root Forwarding 2000 128 P2P Ex0/20 Designated Forwarding 2000 128 P2P NEM-1 SEFOS#
TOR-1 SEFOS# show spanning-tree vlan 10 ------------------------------------------------------------------- Spanning-tree for VLAN 10 Root Id Priority 4106 Address 00:14:4f:6c:6e:0d Cost 2000 Port Ex0/57 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32778 Address 00:14:4f:6c:69:ed Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/1 Alternate Discarding 2000 128 P2P Ex0/57 Root Forwarding 2000 128 P2P TOR-1 SEFOS#
SEFOS-2 SEFOS# show spanning-tree vlan 10 ------------------------------------------------------------------- Spanning-tree for VLAN 10 We are the root of the Spanning Tree Root Id Priority 4106 Address 00:14:4f:6c:6e:0d Cost 0 Port 0 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 4106 Address 00:14:4f:6c:6e:0d Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/1 Designated Forwarding 2000 128 P2P Ex0/57 Designated Forwarding 2000 128 P2P SEFOS-2 SEFOS#
SEFOS-2 SEFOS# configure terminal SEFOS-2 SEFOS(config)# no spanning-tree vlan 10 brg-priority SEFOS-2 SEFOS(config)# end SEFOS-2 SEFOS#
NEM-1 SEFOS# show spanning-tree vlan 10 ------------------------------------------------------------------- Spanning-tree for VLAN 10 We are the root of the Spanning Tree Root Id Priority 32778 Address 00:14:4f:6c:56:6f Cost 0 Port 0 Hello Time 2 Sec, Max Age 20 Sec, Forward Delay 15 Sec Spanning Tree Enabled Protocol PVRST Bridge Id Priority 32778 Address 00:14:4f:6c:56:6f Hello Time 2 sec, Max Age 20 sec, Forward Delay 15 sec Name Role State Cost Prio Type ---- ---- ----- ---- ---- ------ Ex0/3 Designated Forwarding 2000 128 P2P Ex0/7 Designated Forwarding 2000 128 P2P Ex0/20 Designated Forwarding 2000 128 P2P NEM-1 SEFOS#