Can two containers occupy the same host port?

Two containers cannot occupy the same host port simultaneously. A port is a unique identifier at the operating system level, and if one container has already mapped (bound) a host port, another container cannot use the same port.

However, within the Docker network, containers can listen on the same ports because each container has its own network isolation. The issue only arises when ports are mapped to the host machine.

Example: if container A maps port 8080 to the host, container B cannot map port 8080 to the host, but both can listen on port 8080 inside their containers.