Docker / Networking, Ports & Service Connectivity
Use a user-defined Docker network for intended name-based discovery
Containers attached to the same user-defined bridge can use its supported name-resolution behavior. Being on the same host alone is insufficient.
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 appnetRead the result
The inspection lists network configuration and attached endpoints. A matching network still leaves application readiness, ports and aliases to verify.
Resolve and verify
Compare both intended containers' attachments and names, then test the approved application protocol. Correct network membership through the deployment owner.
Before changing production
Do not attach unrelated workloads to one broad network or hard-code changing container IP addresses.