The find-remotes command searches for remotes which claim to provide one or more of the given COLLECTION-ID REF pairs and prints information about them, with remotes sorted by latency (Mounts > LAN > Internet). By default, OSTree searches for remotes in configuration files, on mounted filesystems (in a well-known location), and on the LAN using Avahi. Searching for LAN remotes requires OSTree to have been compiled with Avahi support, and it requires an Avahi daemon to be running. You can override the default set of finders (sources for remotes) using the --finders option documented below.
The create-usb command is the recommended way to put refs on a USB such that find-remotes will discover them. See ostree-create-usb(1).
$ ostree find-remotes --finders=mount,lan com.exampleos.Os exampleos/x86_64/standard
Result 0: http://10.0.64.202:43381/0 - Finder: OstreeRepoFinderAvahi - Keyring: exampleos.trustedkeys.gpg - Priority: 60 - Summary last modified: 2018-01-12T19:00:28Z - Refs: - (com.exampleos.Os, exampleos/x86_64/standard) = c91acd964b3fda561b87bfb7f7c80e36220d76b567f0ce90c0e60742ef33c360 1/1 refs were found.