for keeping syncthing connectity local which one should be turned off?

[vitachaos]

Out of the four above which one can be turned off to not make use of internet for synching ?

[martinleben]

“Enable NAT traversal” “Global Discovery” “Enable Relaying”

But I personally have trouble understanding why anyone wants to disable them, unless when using a metered internet connection.

[vitachaos]

I just discovered my remote raspberry pi got its dns changed in /etc/resolve.conf on reboot that blocked internet connection, which means syncthing basically needs internet connection even if the sync is happening between two hosts within the virtual private network.

[beerse (Corné Beerse)]

My reason to use syncthing only on my local network is that I use syncthing for once-in-a-while-automatic backup. Hence the settings on my mobile devices are relative simple:

• only sync while on wifi (save metered network)
• only sync on my own wifi (save battery while on other wifi)
• only sync while charging (roughly every night)
• Sync from the device is send-only

The other device is my nas (qnap). Which to my idea should not be connectable from the internet.

So yes, all my devices are in ‘Local Discovery’ mode only. Others nat, relay and global are off.

[AudriusButkevicius]

Not sure what you are talking about. Syncthing works perfectly fine without internet connection if configured correctly, in a network that permits it.