How to load balance in this scenario

[Wayne_G]

Real easy one here... 

In the attached diagram, what would be the best way to load balance between the two sites? Note the HP TOR switches don't need to be linked. I'm thinking PVST+. There are only 3 VLANs. Is there anyway to load balance the default VLAN without stacking the switches? 

[Boris Uskov]

Hello

As a matter of fact, I don't see any possibility to load balance default VLAN, without stacking the switches and using etherchannel.

You are absolutaly right, you can load balance with PVST+ by sending one VLAN over the upper link between sites and other two VLANs over the lower link. But the efficiency of the load balancing in this case depends on how the traffic is distributed across VLANs. If the default VLAN is heavy loaded, while other two VLANs are not loaded at all, you won't be able to achieve efficient load balancing in this case.

[devils_advocate]

Unless you can get the switches stacked somehow, your best bet is to use spanning tree by modifying the root bridge per vlan to try and utilise both links.

[Wayne_G]

Thank you both for your reply's. Yes the default vlan is the most used, so won't be perfectly load balanced by running default vlan on one and the other two on the other link. One of the 2 vlans is for voice so at least if the default vlan is fully utilizing one link voice won't be affected (there is qos on the voice as well).