3000 Node/Grafana-default TCP

What it's for

Port 3000 is one of the most common default ports in local web development — the default for many Node.js frameworks (Create React App, Next.js, Express-based starters) and also Grafana's default web UI port. Because so many different tools independently picked 3000 as a sensible default, it's extremely common to have port conflicts when running multiple local projects simultaneously.

Protocol basics

There's nothing protocol-specific about 3000 beyond standard HTTP — it's purely a convention that emerged because it's memorable, easy to type, and outside the range requiring elevated OS privileges. In practice, this means two unrelated tools (say, a React dev server and a local Grafana instance) frequently collide on this port, which is why most frameworks make the port easily configurable via an environment variable or startup flag.