For providing isolated communication between multiple containers running on the same host, distinct from the default network, what kind of custom network should be created?

The kind of custom network that should be created for providing isolated communication between multiple containers running on the same host, distinct from the default network, is a custom bridge network. A bridge network is a core network driver that facilitates communication among containers on the same host. A network driver is the software component that manages how containers connect to networks and interact with each other and the external world. When a custom bridge network is created, Docker establishes a private, internal network segment on the host. This segment acts as a virtual switch, allowing all containers connected to it to communicate directly with each other. The primary advantage of a custom bridge network in this scenario is network isolation. Containers attached to a specific custom bridge network are logically separated from containers on other networks, including Docker's default bridge network, unless explicit port mappings are configured. This isolation ensures that traffic among containers within one custom bridge network does not interfere with or become accessible to containers on other networks, enhancing security and preventing unintended interactions. Another key benefit is automatic service discovery, also known as DNS resolution, within the network. Containers connected to the same custom bridge network can resolve each other's hostnames to IP addresses without additional configuration. For example, if a web application container and a database container are both attached to a custom bridge network named `my-app-net`, the web application can access the database simply by using the database container's name, such as `database-service`, as its hostname. This name-based communication is a significant improvement over the default bridge network, which generally requires communication via IP addresses or deprecated links. To create such a network, the `docker network create` command is used, specifying the `bridge` driver, for example, `docker network create --driver bridge my-isolated-network`. Containers are then attached to this network during their creation, for instance, `docker run --network my-isolated-network --name my-service my-image`. This process ensures that containers requiring collaboration operate within a dedicated, private network, isolated from other host-level traffic and other Docker networks, while simultaneously enabling seamless, name-based communication among themselves.