Somewhere in the app we should be able to locate both the MAC code and IP address. I have nearly 100 devices on my network and keeping track of them (and keeping my network secure) is a pain when I cannot easily find identifying information. Thanks!
MAC address is already made available via the app. Look under device settings either via a website https://app.rach.io/ or Android / iOS applications.
Not sure what you could do with information on the IP address. Rachio does not make any useful data / interface available directly via the controller.
With such large network, I recommend you get one of the free network scanning applications, such as Fing (for iOS) or (for Android). It had no issues not only quickly locating the MAC / IP information, but also correctly identifying it as a Rachio controller.