VPS Tutorials
VPS Port Already in Use (2026): Address already in use, EADDRINUSE, Docker/Nginx Conflict Troubleshooting
When starting a service on a VPS you see Address already in use, EADDRINUSE, bind() failed, or Docker port is already allocated. Common causes include an old process that never exited, Nginx/Apache/Caddy grabbing 80/443, Docker port mapping conflicts, IPv4/IPv6 dual-stack listening confusion, duplicate systemd service starts, or misreading TIME_WAIT. This article troubleshoots layer by layer using ss, lsof, fuser, journalctl, Docker, and Nginx logs.
