Switches, Hubs, and Modems
cancel
Showing results for 
Search instead for 
Did you mean: 

multi vlan stp

Alessio Zarb
Advisor

multi vlan stp

any one can help me on this.i have a 3 port router one is for the wan conectivity and the others are 2 different lan subnets conected with 2 diffeernet uplinks on a single hp switch .as i split any hp switch with vlans while having stp running, one of the uplinks is blocked.

i think this is becouse stp dosent support multi vlan .
any ideas how to solve this issue without using tagging in the process
9 REPLIES
Kell van Daal
Respected Contributor

Re: multi vlan stp

Are the uplinks directly connected to the router? If so, none of the ports should be blocked since a router normally doesn't have STP running.
If your router is running STP, disable it. As I read your setup, your router doesn't have any bridge interface, so it shouldn't be nessecary.
Alessio Zarb
Advisor

Re: multi vlan stp

yes the uplinks are directly conected.and no stp isnt running on the router.the only thing is that i have more then one switch behind the router and the vlans keep going till the last switch.

the blocking is happening at swi 3 as showen in the atteched diagram.
Kell van Daal
Respected Contributor

Re: multi vlan stp

Hi Alessio,

It's more clear now with the drawing.
What kind of switches do you have?
If the switches support MST (multiple instance spanning tree), then that could be your savior. Just assign both VLAN's in their own instance.

If they do not support that, then disabling STP is your only option.
Alessio Zarb
Advisor

Re: multi vlan stp

thanks anyway as i allready said further up this message it might be this the problem ,do hp have any patches for their switchs that support mtsp?as they only support rstp/stp

thanks again ......
Kell van Daal
Respected Contributor

Re: multi vlan stp

Depends on which type of switches you have.
Some switches get MST functionality with a firmware upgrade, some don't.
The 5300xl and the 2600 series for example have MST support. The 4100gl and the 2500 series for example do not have MST support.

So what series of switches do you have?
Regnar Bang Lyngsø_2
Frequent Advisor

Re: multi vlan stp

Why do you want to avoid tagging? In a single instance spanning tree setup you will usually use link aggregation (e.g., LACP) and vlan tagging between the switches.

Regnar
Kell van Daal
Respected Contributor

Re: multi vlan stp

I cannot speak for the topicstarter, but a reason to avoid tagging, is to make sure a VLAN has dedicated (100 Mbit/1 Gbit, depends on the link) bandwidth.
When using LACP or something similar, and then tag the traffic won't get you that garantuee.
I agree that there are very few situations I would work like that, but I can imagine some situations where it would be preferable.

But it's still a good question. Maybe the reason why the topicstarter doesn't want to use tagging, is something that can be solved easier.
Alessio Zarb
Advisor

Re: multi vlan stp

my problem is that we have loads of networks like this ,as primerily we where using hubs but now a days its not worth it to buy a hub.

thus every hub which goes faulty will be replced with a switch. and thats why the problem started.

I know it is better to use tagging but to change over all these old networks would cost loads of money to the customer involved.

since we are using hp2524s it would be great to use the same equipment for both lans

thanks a lot to every one


Alessio Zarb
Advisor

Re: multi vlan stp

thanks to all