Docker / Networking, Ports & Service Connectivity
Investigate Docker traffic through its actual firewall integration
Docker-managed networking can create rules beyond a host administrator's simplified firewall view. Inspect the network and platform documentation.
Environment and inputs: Docker Engine · Compose v2 and Buildx where specified; Linux containers unless noted. Verify daemon context, installed feature support and authorized host or Swarm manager access first.
Start with this check
Confirm the environment and replace sample objects, namespaces, images, paths and hosts with approved targets. Share only relevant, sanitized output. Follow the workload owner’s process for changes.
docker network inspect --format '{{.Driver}} {{json .Options}}' appnetRead the result
The selected driver identifies part of the forwarding path. It does not list all host rules, bridge filtering, routing or external firewall policy.
Resolve and verify
Correlate the actual allowed or denied flow with Docker's supported firewall integration and host logs. Make narrow changes through the managing security workflow.
Before changing production
Do not flush Docker rules or assume an ordinary host input rule alone governs every published container port.