STP, PVST & MSTP

[william2u]

Hi all the guru, i got 2 swtiches here. Cisco 3524 & Huawei 3900. I got three vLAN, which is VLAN 100 , 200 & 300. By default, Cisco are running PVST. Huawei is running IEEE STP, how can they talk to each other, without changing any configuration on Cisco site. Can Huawei run MSTP and divide each vlan into different instance to match PVST ? coz in PVST, each vLan have its own STP. Do you think its work like this ??? or any other good sugestion ?

[leonvd79]

Cisco run's PVST by default. If you cannot change the configuration of the Cisco Catalyts switch, your best option is to run 802.1d CST on the Huawei switch.

As Per-VLAN Spanning Tree is a Cisco proprietary technology - and the only STP version supported on the 3500XL platfrom, Huawei cannot be configured for MST either.

HTH

Leon

* Please rate posts

[william2u]

Huawei do support MST, but if Huawei is 802.1d CST and cisco PVST... can all my vlan talk perfectly ???

[leonvd79]

Yes, Cisco PVST is compatible with IEEE 802.1d CST. The switchport that connects to the Huawei switch sends 802.1d BPDU hello on that link.

[william2u]

i dun think it will work. if the link is TRUNK link, coz in TRUNK, every VLAN has its own STP. but CST is not.... the this 2 switch cant talk to each other...

am i rite?

[Francois Tallet]

The Cisco box will consider the Huawei as a hub for vlan 100, 200, 300. If there is no vlan 1 on your 3524, the Huawei will just not see the Cisco bridge.

So it will be the Cisco bridge that will block any potential loop between the two bridges, and you will be able to do some load balancing per-vlan configuring PVST. Convergence time wise, don't expect stellar result as this will regular STP calculation.

If the 3524 does not run MST, there is nothing much else you can do unfortunately...

Regards,

Francois

[william2u]

Huawei do support CST, MSTP & RSTP. what can i do ????? without changing CISCO STP configuration ....... to let all VLAN communicate and enable vLAN 300 priority in HUAWEI and 100 & 200 priority on Cisco.........

[Francois Tallet]

You don't have to do anything, it should work by default. However, your configuration options are just a subset of what they should be if the cisco device was able to run MST.

What do you mean exactly by "enable vlan 300 priority in HUAWEI and 100 & 200 priority on Cisco" ? If you give us more details on what your setup is exactly (and what you are trying to achieve), we should be able to help.

Regards,

Francois