Mac mini server as AP

Sorry. It's not really possible to turn a mini into a normal wifi AP. There is no provision in OSX to send SSID beacons. It's network stack is wifi client only.

You might want to check out dd-wrt. Open source linux based wifi for many popular APs. The last used netgear router I bought to run dd-wrt cost $35.

if you want to roll your own, depending on the size of your network you'd be better off using a raspberry pi

it would use far less power about 5w i think

Ummm - It sounds like you may be defining AP in an unusual way.

If you want to run Radius on an OSX server here is a link with set up instructions:

http://krypted.com/mac-security/configure-radius-in-mavericks-server/

The Mac has the built-in ability to 'share' its Internet connection via an additional interface in this case WiFi. However while this does operate in 'infrastructure' mode - the better mode unlike Windows which only does 'ad-hoc' mode it is still not as sophisticated as a real full-blown base-station. As mentioned by Ren McCourtey it is only capable of WPA Personal and hence cannot be linked to RADIUS.

This might change in the future but for the moment an option would be to run a Linux virtual machine on the Mac and have Linux do all this (which it can), you could even have the Linux side use the Mac RADIUS server which is the standard open-source FreeRADIUS software (also available for Linux).

The cost of a real Apple AirPort Extreme is not excessive, get a real base-station.

OS X does what it does, and usually does it quite well.

If you need something else and are headed toward customizations and extensions and add-on software packages, then Linux or BSD is probably going to be a better and more flexible choice to build on, and for cases such as this particularly given that there are available distributions such as DD-WRT, Tomato or OpenWRT around. I'd likely start with one of these three or an equivalent, as that looks like the best fit for what you're after.

Further up the gonzo scale are the Synology NAS boxes. All sorts of features can be added to these boxes.

With OS X itself, more than a few folks have slammed into various configuration and support issues, trying to run a server as a NAT box or router, and running it as a WiFi AP is likely no different — OS X and OS X Server are just not very good at supporting the sorts of wholesale customizations that other some alternative operating systems can support or even expect, IMHO.

What I posted above is wrong. I did not know that internet connection sharing was able to place a Mac into AP mode.

Apologies for my error.

Has anyone tried out John Lockwood's idea of running a Linux based AP in a VM on a Mac?

It would be a great way to debug and maintain a build of dd-wrt or the like. If the AP could be built to run in a VM with a console instead of just on routter boxes development would be much easier.

I tend to use Time Capsule as an Access Point, and that works quite nicely, and also provides an off-host backup target for Time Machine.

AirPort also works well here; I have a few configured that way, as well.

An AirPort or Time Capsule configured as an Access Point isn't particularly useful as a gateway, though.

The PC Engines ALIX Geode-based boxes are pretty nice for small servers. (Haven't looked at the NUC, however.)

I have a macmini 2011 (no server version) upgraded to 16GB memory and a SSD main hardisk, running the server.app at home and controling the network access in RADIUS mode. it works perfectly as a server, but as AP is not the way it was design, so you can do it but you will find thousand walls on your way.

to config easily the RADIUS under the server.app, there is an additional app in Apple Store "Admin Tool RADIUS" which makes your life easier for $2, instead of drawing on Terminal command line.