I do a lot of testing on MacBook Airs and the latest MacBooks. Neither have a built-in Ethernet port and I try not to travel with one. But, when you enable the Caching Server service in OS X on a machine without an active Ethernet connection, the AssetCache will report an error of the following:
Wireless portable computer not supported
The cause is pretty obvious, but bypassable because of how the sanity check was built. Simply run the following:
sudo serveradmin settings caching:Interface = en0
Now try again. Enjoy.
PS: Since people always jump on the article where I talk about how to do things that shouldn’t be done in production, I mostly use this for testing. Don’t do it in production… And if you enjoy being judgmental about things, please feel free to find something constructive to do with your time, like write up how to do something that everyone else can judge you harshly for…