Range-based allocation allows you to specify OUI-based Locally Administered Address (LAA) ranges that can be set to include or exclude specific ranges. You specify one or more ranges using a minimum starting point and a maximum ending point, such as (005068000002, 0050680000ff). MAC addresses are generated only from within the specified range.

This scheme is supported on ESXi hosts 5.1 and later.

You can specify multiple sets of LAA ranges. The number of MAC addresses in use are tracked for each range that is defined. MAC addresses are allocated from the first defined range set that still has addresses available. After MAC addresses are allocated, the information is recorded in the vCenter Server database. This allows vCenter Server to check for MAC address collision within the ranges assigned to that vCenter Server.

When using range-based allocation, you must provide different instances of vCenter Server with ranges that do not overlap. vCenter Server does not detect ranges that might conflict with ranges used by other vCenter Server instances.