Port 8008: HTTP-alt

Port 8008 is commonly used as an alternate, unprivileged HTTP port, and it is also the port Chromecast and other Google Cast devices use for local discovery and control over the DIAL protocol. It is not a fixed IANA assignment, just a widely followed convention.

TCPWebUnencrypted by default
Port number8008
ServiceAlternate HTTP / Google Cast discovery
ProtocolTCP
CategoryWeb
Default encryptionNo
Security note. Port 8008 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.

How do I check whether port 8008 is open?

Port 8008 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.

QuestionCommandWhat to know
Is it open on a remote host?nc -vz example.com 8008A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line.
Same check on WindowsTest-NetConnection example.com -Port 8008Built 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 ':8008 'Lists the process bound to port 8008 on Linux. On macOS use lsof -nP -iTCP:8008 -sTCP:LISTEN, on Windows netstat -ano | findstr :8008

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 8008 used for?

Port 8008 is commonly used as an alternate, unprivileged HTTP port, and it is also the port Chromecast and other Google Cast devices use for local discovery and control over the DIAL protocol. It is not a fixed IANA assignment, just a widely followed convention.

Is port 8008 TCP or UDP?

Port 8008 (HTTP-alt) uses TCP.

Is port 8008 secure?

Port 8008 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 8008 on my firewall?

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