This is what I have on the CP Guest subject in regards of licensing.
Clearpass Guest
Guest is special, the MAC addresses refresh per day. You end up with a weekly view so that you can see a daily average though. We understand that in guest environments users come and go on a much quicker basis than in the enterprise itself.
The policy manager tracks the unique MAC addresses that it sees on a daily basis, but the refresh is weekly
From <http://community.arubanetworks.com/t5/AAA-NAC-Guest-Access-BYOD/Clearpass-Guest-Licensing-Question/td-p/88392/highlight/true/page/2>
Guest uses a daily reset model. If you have 1 appliance and use the starter bundle (25 licenses) all for guest, you can authenticate 25 unique MAC addresses per day that are connected by guests (we support bursting so that if you have not purchased the right level of licenses, users are not denied access). The next day you may see some of the same MAC addresses and new ones. If you stay under or at 25 authentications you have enough licensing (again bursting is supported).
The problem starts when you consistently see 30/40/90 authentications per day over 3 months. Then it's time to buy the next level license bundle.
Trent
ClearPass Product Management
From <http://community.arubanetworks.com/t5/AAA-NAC-Guest-Access-BYOD/Clearpass-Guest-Licensing-Question/td-p/88392/highlight/true/page/2>
Note that if you allow more than 1 device connected/active per guestaccount - each device consumes one license.
If you're looking at 2k regular with some peaks than it seems like CP-VW/HW-5K should do the job server wise. For Guest the system isn't hard-limited to 1k Guests so start with say 1000 licenses and buy more once you get a clearer picture of the use.