Resilio Connect can function in LAN without internet access.
Resilio Connect utilizes peer-to-peer technology to share files between devices, which means that all the data that is transferred by Resilio Connect Agents is stored on users’ equipment only. This mechanism provides more control over your data and a much higher level of security. At the same time, peer-to-peer technology requires you to exercise additional caution while picking your data recipients. Since all the transfer occurs between you and other peers - Resilio neither hosts nor caches any content - there’s no way to modify or remove your data other than modifying or removing it on your device(s) and the device(s) of your peer(s). The entire process of sharing occurs directly between you and other users with next to zero involvement of Resilio.
We cannot see your files. However, there is one point of contact with Resilio Inc. infrastructure: Tracker server (if you do not use embedded one) - this service allows for peers to find each other under normal network conditions. Once peers learn each other's address, they try to connect to each other directly. Peers communicate their IP addresses and listening ports to tracker, together with a share's ID. Peres know the share's ID from share's link. So a random device won't know your address unless it has the same shareID communicated to tracker.