Have a delima with max vlans. We're a service provider, and as such, we give each customer their own dedicated subnet and VLAN. The basic topology is 4500's as distribution switches and 2960's as access switches. We have ESX hosts running off of the 2960's. Currently, we're running PVST, but the 2960's support a max of 128 instances which we're nearing, so we are looking to switch to MST or more likely, flex links.
However, the vlan database currently has 200 VLANs and we're nearly exhausted there, so I plan on adding more. The limit of the 2960's is255 VLANs though. The problem is, with a massive ESX cluster, the VM's might be any any of the ESX hosts, and therefore, I have to have every VLAN on every switch. The 2960 access switches don't have any access ports tagged with those VLAN's, they just have a trunk port to the ESX host, and a trunk port up to the distribution switches. I wouldn't need to do any VLAN pruning or limit the VLAN's being sent across the trunk ports.
If I switch from a VTP domain to VTP transparent mode, do the 2960's still have to have a VLAN in their local database in order to carry it over their trunk ports to the ESX hosts or are they smart enough to just pass the already tagged VLAN traffic across the trunk ports up to the 4500's, which would effectively let me bypass the limit of 255.
I'd rather not have to double up customers on VLAN's (security concerns) or go out and purchase all new 3750's to replace all of the2960's (don't have that kind of budget). Is there anything I'm missing that would make this solution work?