Assume I have a node A running syncthing and sharing a repository R in master mode. On another node B on the same LAN I connect to R. On node A I share the repo to B. The contents are now synched from A to B.
Now I add a third node C and connect it to R. On node A I share the repo to C. Are the contents are now synched just from A to C, or also from B to C (assuming B still has the unmodified contents from A)? In other words: do all nodes that carry a specific repository participate in data exchange even though they (officially) do no know each other?