Why might the connection between an application running in a Docker container and a database located in another network segment be interrupted despite an open connection?

Even if the connection between a Dockerized application and a database in another network segment is open, it can be interrupted for several reasons:

• Network restrictions and firewalls: Rules may be set up between segments that break connections after a certain period of inactivity.
• NAT and timeouts: If NAT is used, intermediate devices may close inactive connections.
• DNS or routing issues: If the container cannot resolve the database address correctly or routes are unstable.
• Container resources: Memory or CPU limitations can cause network stack failures.
• TCP keep-alive settings: If not configured, the connection can be closed due to inactivity.

To resolve the issue, check network policies, configure TCP keep-alive, ensure correct routing, and network stability between segments.