Comware - PVST+

1.      STP and RSTP cannot load balance, therefore PVST created by Cisco. 

            Protoco            Developer               VLAN ID
            MSTP               IEEE (802.1Q)         802.1Q
            PVST                Cisco                        ISL
            PVST+              Cisco                        802.1Q

2.       Comware v5 implements MSTP

3.       New software releases add PVST+ to Comware v5 switches

Configuration Steps

1.       Configure 3 VLANs

2. Create a spanning tree per VLAN
3. Configure

•       Switch A as root of VLAN 1

•       Switch B as root of VLAN 2

•       Switch C as root of VLAN 3 

4. Note: in this example it is assumed that Switch A has the smallest default Bridge-ID

Test Layout

1.        Configure all VLANs

2. Enable STP in system-view

stp enable 

3.       Change the STP mode to PVST

stp mode pvst

4.       Connect the switches 

Notes

The STP default mode is MSTP

At this point a Spanning Tree has been created for each VLAN. All spanning trees have the same root

5. Change the bridge priority for individual VLANs or for lists of VLANs

stp vlan vlan-list priority priority value

Figure 1: Test Network Layout

1.    On all three switches

a.    Create VLANs 2-6

b.    Configure ports 1 and 2 as “link-type trunk” permitting all VLANs

c.    Enable STP

d.    Change STP mode to PVST+

2.    Connect Cables following figure 1.

Commands

system-view

 vlan 2 to 6

 interface gigabit 0/1

  port link-type trunk

  port trunk permit vlan all

  quit

 interface gigabit 0/2

  port link-type trunk

  port trunk permit vlan all

  quit

 stp enable

 stp mode pvst

 quit

3.    Check the stp configuration. Notice that the root bridge for all STP instances is the same.

Commands

display stp root

display stp brief

4.    Change the root of different instances:

a.    Switch 1: VLAN 1 and 2

b.    Switch 2: VLAN 3 and 4

c.    Switch 3: VLAN 5 and 6

Example

Switch A:

system-view

 stp vlan 1 priority 4096

 quit

Switch B:

system-view

 stp vlan 2 priority 4096

 quit

Switch C:

system-view

 stp vlan 3 priority 4096

 quit

Result 

1.    Verify that the root bridges changed

Commands

display stp root

display stp brief