Port 2379: etcd
Port 2379 is the client port for etcd, the distributed key-value store that Kubernetes uses to store all of its cluster state. Anyone who can read from etcd can effectively read every Kubernetes secret, so this port needs strict access control.
| Port number | 2379 |
|---|---|
| Service | etcd client API |
| Protocol | TCP |
| Category | Infrastructure & orchestration |
| Default encryption | No |
How do I check whether port 2379 is open?
Port 2379 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.
| Question | Command | What to know |
|---|---|---|
| Is it open on a remote host? | nc -vz example.com 2379 | A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line. |
| Same check on Windows | Test-NetConnection example.com -Port 2379 | Built into PowerShell. TcpTestSucceeded in the output is the answer; telnet is not installed by default on modern Windows. |
| What is listening locally? | ss -tlnp | grep ':2379 ' | Lists the process bound to port 2379 on Linux. On macOS use lsof -nP -iTCP:2379 -sTCP:LISTEN, on Windows netstat -ano | findstr :2379 |
Replace example.com with the host you are testing. A blocked port and a port with nothing listening on it look identical from the outside, so if a service should be running, check locally before blaming the firewall.
Frequently asked questions
What is port 2379 used for?
Port 2379 is the client port for etcd, the distributed key-value store that Kubernetes uses to store all of its cluster state. Anyone who can read from etcd can effectively read every Kubernetes secret, so this port needs strict access control.
Is port 2379 TCP or UDP?
Port 2379 (etcd) uses TCP.
Is port 2379 secure?
Port 2379 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 2379 on my firewall?
Only if you specifically need etcd. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.