One possible "run" would be something akin to this:
- device boots up and configures itself as an EthernetClient
- scans for a specific server on the network
- if found, requests a data file and downloads it to its onboard SD card
- if the server isn't found, reconfigure itself as a listening server and jump in it's normal loop
(the purpose of each one being a listening server is so I can poll them later and retrieve status information from each one, as opposed to having them constantly send stuff out.)
This way I don't have to be scanning for that server during a program run, but only when the thing boots up (or gets reset). Very much like what a bootloader does, either go into programming mode, or run the sketch.