I have made the mistake of making a supply line web by making each of my settlements (14 as of now) connect to every available settlement (e.g. connected Red Rocket to all settlements. connected Hangman Alley to all settlements. and so on).

Is there a way to cancel all supply lines without waiting for the provitioner to return to the settlement to be reassigned?

Already tried the bell as well as the other things I found at google but I'm looking for a more efficient way of doing it.

I can't answer. I thought from the subject that this thread would be about supply lines cancelling ~unexpectedly~.

I set up a Supply Line from the Slog to the nearby greenhouse settlement and of course my Workshop access tied into the Supply Web and I had 1,200 steel to craft at the new base. I started dropping turrets and then suddenly I had only 11 steel!?!? I wondered what was going on, backed up a few levels then went back and all of a sudden I had 1,000+ steel available again.... placed a few things and then it's back down to the steel on my person.

I finally realized that there was a Mister Gutsy just down the road that was whacking every provisioner that left The Slog heading that way to "establish" the supply line. A new settler apparently took up the supply route shortly, but then was cut down my the Mister Gutsy and I lost my connection to the supply web again.

I WOULD like to know the actual answer to your question, though, because I also created a giant interdependent web of supply lines ---- probalby fifty Provisioners running around the Commonwealth now. On my next run, I'll definitely limit my number of "links".

Currently, there's no way to cancel supply routes outside of finding the provisioner and manually assigning him within your settlement.

The system needs some serious tweaking. Like, a terminal which highlights inbound and outbound caravans would be a good idea... (how does this idea not even come up during QA sessions - jesus Bethesda).

yeah, your caravans do get attacked, and WILL get attacked, as they go through some of the most dangerous areas of the game. (I followed one once and she walked through every flipping supermutant camp and deathclaw den in the game) I wish you could assign caravan guards to each of them