6308m-SX+three 8000m

[Andrew_291]

Hello All !

There is a liitle problem . I have three ProCurve 8000m switches connected by 100BaseT trunks . Each of them contains four VLAN and trunks are tagged on all VLANs . Each of 8000m connected to a neighbour switch with a two trunk and because STP enabled and one switch have BID less than other - redundant trunks are blocked and network works fine.

I want to connect all three switches thru the existing 6308SX and stay connected them with the 100BaseT trunks . 1000BaseSX modules are installed already in switches on slot I and I1 port tagged on each VLAN.Two of switches have default BID for STP - 32768 and rest one (it is root now) - 8192 . 8000m will connect to 6308sx on ports from e1 to e3.

On 6308SX I make next configuration for stp and vlans -
--------------------------------------------

HP6308(config)#sho ru
Current configuration:
!
ver 06.6.36T43
!
span single
spanning-tree priority 1024
global-protocol-vlan
!
!
vlan 3999 name DEFAULT-VLAN by port
!
vlan 4 by port
tagged ethe 1 to 3
!
vlan 2 by port
tagged ethe 1 to 3
!
vlan 3 by port
tagged ethe 1 to 3
!
vlan 1 by port
tagged ethe 1 to 3
!
default-vlan-id 3999
!
tag-type 00e1
!
end

HP6308(config)#
--------------------------------------------

Will that works or not ? Will be 6308SX as root bridge for all four vlans ? May be single STP not is good choice ? Would be better configure 6308sx with multiple STP on each VLAN ? Experts, please give me an aswer 8))) because I am novice in PVSTP (who exist on 6308sx)
I attach little picture with a scheme of network..sorry but painting is mistery for me..

Great thanks.
Andrew.

[Kell van Daal · Accepted solution]

Hi Andrew,

The setup you provided will work. The 6308 will be rootbridge. Since single instance spanningtree does not take VLAN's into account, you could say: yes, it is the rootbridge for all four VLAN's.

The question if you should use PVST has an easy answer: No
The 8000 switches do not support PVST (or MST).

Chances are big that even if the 8000 switches would support it, you wouldn't need/want PVST.
Seeing your excellent drawed picture ;) I assume almost all traffic would go from a 8000 to the 6308 and back, with not a lot of traffic between the 8000 switches themselves. That would mean that the best way for traffic would allways be the same: The SX connections. Even traffic between 8000 switches have more bandwidth through the 6308. PVST is used to enable "loadbalancing" for traffic, by dividing traffic from different VLAN's over different connections. And as I doubt that is the case, your setup is sufficient.

(note that the last paragraph is based on an assumption about traffic flows, so it doesn't have to be true in your case)

[Andrew_291]

Great thanks .
Scheme drown on my picture really works.