Keeping folders synced between several machines
I am wondering if there is such a thing as software that:
- Synchronizes user-specified folders between my four (Windows) computers
- Syncs over LAN if possible and internet if not
- Does not use cloud storage or a third-party server to sync
Cloud storage is costly and limits the volume of data I can sync. It also slows down the synchronization to uploading data to an unnecessary fifth computer, especially when I'm just syncing over LAN and that computer would be remote. (As far as offsite backup goes, I'm already running a cross backup with a friend, so I don't even want additional cloud space.) I would like it to be fast if possible since I have a gigabit LAN in mind.
I've looked and looked at various software. Everything seems to be geared towards more conventional cloud backup or is restricted to LAN or has some other usage constraints. It's getting so that I'm feeling like writing my own sync software - am I the first to have these ideas? - but I have time restraints due to real life.
I'm asking if any solution for this even exists right now. Does anyone have any experience in setting up this kind of thing that could help point me in the right direction?