Port 2375 — Docker API (plain)
TCP registered
What runs on port 2375
The Docker daemon REST API without TLS.
Security considerations
Exposing this is equivalent to handing out root on the host. It is one of the most scanned ports on the internet for exactly that reason. Use the Unix socket, or 2376 with client certificates.
Checking whether something is listening
# Linux / macOS — what is bound to the port
sudo lsof -i :2375
sudo ss -lntp | grep :2375
# Windows
netstat -ano | findstr :2375
Get-NetTCPConnection -LocalPort 2375
# is it reachable from outside?
nc -zv example.com 2375
curl -v telnet://example.com:2375
Freeing the port
# find the process, then stop it
sudo lsof -ti :2375 | xargs kill # Linux / macOS
netstat -ano | findstr :2375 # note the PID, then:
taskkill /PID <pid> /F # Windows
Should this port be open to the internet?
No. Port 2375 should never be reachable from a public address. Bind it to localhost or a private network, and reach it through a VPN or bastion host if remote access is genuinely needed. Internet-wide scanners find newly exposed instances of this service within minutes.
Quick reference
| Port | 2375 |
| Protocol | TCP |
| Service | Docker API (plain) |
| Range | Registered (1024–49151) — any user process may bind |
Frequently asked questions
What is port 2375 used for?
The Docker daemon REST API without TLS.
Is it safe to open port 2375?
Exposing this is equivalent to handing out root on the host. It is one of the most scanned ports on the internet for exactly that reason. Use the Unix socket, or 2376 with client certificates.
How do I check if port 2375 is open?
Locally, sudo lsof -i :2375 on macOS or Linux, or netstat -ano | findstr :2375 on Windows. From outside, nc -zv host 2375 tells you whether anything answers.
Why do I get "address already in use" on port 2375?
Another process is bound to it — often a previous run of your own program that did not exit cleanly. Find it with lsof -ti :2375 and stop it, or configure your application to use a different port.
Can I change the port this service uses?
Almost always yes, in the service's configuration. Moving off a default port reduces automated scan noise, but it is obfuscation rather than security — a real attacker scans all 65,535.