Docker Swarm High Availability

Hi, I am new to Docker but an old IT admin who have worked a lot in virtual environments.
I am trying to build a highly available swarm with three physical computers on the same subnet.
What I still haven’t figured out is how a swarm handles a situation where the LAN gets isolated so that Docker Hub can not be reached and then I have one of the physical computers go offline.
Is there some way to force all the workers to download all Docker images that are used in the Swarm making the cluster self-sufficient in case of a loss of internet connection?

If you have the same service running on all nodes, then they all have the image, and dosnt need to pull from hub.

Alternatively, you could create your own “docker hub” (registry) locally, and have all images that you use, on that.