Port 5432: PostgreSQL
Port 5432 is the default PostgreSQL listener. As with any database, limit it to application servers and require TLS and strong credentials.
| Port number | 5432 |
|---|---|
| Service | PostgreSQL database |
| Protocol | TCP |
| Category | Databases |
| Default encryption | No |
How do I check whether port 5432 is open?
Port 5432 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 5432 | 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 5432 | 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 ':5432 ' | Lists the process bound to port 5432 on Linux. On macOS use lsof -nP -iTCP:5432 -sTCP:LISTEN, on Windows netstat -ano | findstr :5432 |
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 5432 used for?
Port 5432 is the default PostgreSQL listener. As with any database, limit it to application servers and require TLS and strong credentials.
Is port 5432 TCP or UDP?
Port 5432 (PostgreSQL) uses TCP.
Is port 5432 secure?
Port 5432 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 5432 on my firewall?
Only if you specifically need PostgreSQL. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.