All ports
Port591/TCP
http-altPort
591
Protocol
TCP
Category
Well-Known
Service
http-alt
What is port 591?
Port 591/TCP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the http-alt service.
FileMaker, Inc. - HTTP Alternate (see Port 80)
Useful commands
nmapnmap -p 591 -sV example.comnetcatnc -zv example.com 591curlcurl -v http://example.com:591/telnettelnet example.com 591bash(echo > /dev/tcp/example.com/591) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 591/tcpDeny
sudo ufw deny 591/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 591 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 591 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=591/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 591" dir=in action=allow protocol=TCP localport=591Security Risks
- SQL injection and cross-site scripting (XSS)
- Exposure of sensitive data due to lack of encryption
- Denial of service attacks (DoS)
- Directory traversal and exposure of sensitive files
- Brute force attacks against authentication forms
Frequently Asked Questions
What service runs on port 591/TCP?
Port 591/TCP is associated with the http-alt service. FileMaker, Inc. - HTTP Alternate (see Port 80)
Is it safe to expose port 591 to the Internet?
It depends on the service and configuration. Port 591 (http-alt) is a Well-Known port. If you need to expose it, keep the service updated, use strong authentication, and configure a firewall. It's always recommended to restrict access by IP when possible.
How do I check if port 591 is open?
You can use nmap: `nmap -p 591 -sV example.com`, netcat: `nc -zv example.com 591`, or the bash command: `(echo > /dev/tcp/example.com/591) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 591 on my firewall?
On Linux with UFW: `sudo ufw allow 591/tcp` (open) or `sudo ufw deny 591/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 591 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 591" dir=in action=allow protocol=TCP localport=591`.
What applications and services use port 591?
Port 591/TCP is used by the http-alt service. Specific uses depend on the software and configuration. Check our related tools section for more information.