Port 19: Chargen

Port 19 is the Character Generator Protocol, which streams a continuous sequence of characters back to the client. It is best known today as a target for UDP amplification attacks, so it should never be exposed to the internet.

TCP/UDPLegacy protocolsUnencrypted by defaultIANA assigned
Port number19
ServiceCharacter Generator Protocol
ProtocolTCP/UDP
CategoryLegacy protocols
Default encryptionNo
Security note. Port 19 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 19 used for?

Port 19 is the Character Generator Protocol, which streams a continuous sequence of characters back to the client. It is best known today as a target for UDP amplification attacks, so it should never be exposed to the internet.

Is port 19 TCP or UDP?

Port 19 (Chargen) uses TCP/UDP.

Is port 19 secure?

Port 19 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 19 on my firewall?

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