seeking for design assistance and moving to the latest available hardware to cope with business growth. New design should Cover redundancy, growth, security and simplifying Management.
our current infrastructure comprises of 6506 as core + distribution, 2960 as the access layer, WAN Block / Internet Block / Server Block / Management Block. In all there is 50 National sites connected via MPLS, 30 International sites connection via VPN. core application are centralized
in general Cisco 65K with SUP2T is very good option for core/distribution of a campus where nexus 7K for large DC is the choice for the core/distribution of a DC and 5K with L3 can be used a access/distribution for small DC 2K in both cases can be used to expand the access ports density for ToR of needed
if your network is big you can use the modular campus design described in the link i provided above where your Internet and WAN can be placed in one block with aggregation switch and routers for connectivity
managment can be placed in the DC or services block
if your network is small you can use collapsed design where you can combine multiple blocks into one using a pair of 65K or 45K switches
also VSS is very important capability you need to consider if your going to use 65K in your design