Regarding docker network

I have multiple containers(total 6) running on network net1 and only 1 container which runs with –net host flag.

One of the multiple containers is ‘RestAPI container’… and the one which runs with –net host is ‘Protocol Container’

When I start the containers for the first time with fresh environment (removing all volumes… and containers) I am able to ping the Protocol container from RestAPI container. When I restart the host machine(Ubuntu 20.04) I observe that the RestAPI container is able to ping other containers in its n/w but not able to ping the Protocol container.

I don’t use docker compose I have written a shell script to run the containers.

OS: Ubuntu 20.04
Docker Version: 20.10.22

How do you “ping” the protocol container if that is using the host network? Host network means the container does not have its own ip address. In other words is is not isolated in terms of network so you can only ping the host.

If you could do that without volumes, then you probably mounted a config file which changed something, but we could only guess. Can you share mor einformation what exactly you did and how? Please describe it step by step with commands using code blocks

like this

and share more information about the mounted files, what kind of config files those were.