Port 20000: DNP3

Port 20000 is DNP3, a protocol widely used in electric and water utility SCADA systems to communicate between control centers and remote field equipment. Like many older industrial protocols, it was not designed with modern network security in mind.

TCP/UDPIoT & automationUnencrypted by defaultIANA assigned
Port number20000
ServiceDistributed Network Protocol 3
ProtocolTCP/UDP
CategoryIoT & automation
Default encryptionNo
Security note. Port 20000 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.

Frequently asked questions

What is port 20000 used for?

Port 20000 is DNP3, a protocol widely used in electric and water utility SCADA systems to communicate between control centers and remote field equipment. Like many older industrial protocols, it was not designed with modern network security in mind.

Is port 20000 TCP or UDP?

Port 20000 (DNP3) uses TCP/UDP.

Is port 20000 secure?

Port 20000 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 20000 on my firewall?

Only if you specifically need DNP3. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.