Simple question. I am having trouble finding documentation on how to configure l2tp on a 4500 series switch. Basically the idea is to extend the VLAN's on 4507 across a layer 3 network to another 4507.
I don't think L2TP is supported on switches (except maybe on 6500 with VPN SPA module). The only way to extend VLANs across L3 network that I can think of right now is using VPLS (VPLS = Virtual Private LAN Service)- essentially VLAN/Ethernet over MPLS.