All ports
Port3551/UDP
apcupsdPort
3551
Protocol
UDP
Category
Registered
Service
apcupsd
What is port 3551?
Port 3551/UDP is a Registered port, registered with IANA for specific applications. It is associated with the apcupsd service.
Apcupsd Information Port
Useful commands
nmapnmap -p 3551 -sV example.comnetcatnc -zv example.com 3551curlcurl -v http://example.com:3551/telnettelnet example.com 3551bash(echo > /dev/udp/example.com/3551) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3551/udpDeny
sudo ufw deny 3551/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3551 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3551 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3551/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3551" dir=in action=allow protocol=UDP localport=3551Security Risks
- Unauthorized access to the service
- Data exposure if the service is unauthenticated
- Outdated versions with vulnerabilities
- Incorrect service configuration
Frequently Asked Questions
What service runs on port 3551/UDP?
Port 3551/UDP is associated with the apcupsd service. Apcupsd Information Port
Is it safe to expose port 3551 to the Internet?
It depends on the service and configuration. Port 3551 (apcupsd) is a Registered 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 3551 is open?
You can use nmap: `nmap -p 3551 -sV example.com`, netcat: `nc -zv example.com 3551`, or the bash command: `(echo > /dev/udp/example.com/3551) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3551 on my firewall?
On Linux with UFW: `sudo ufw allow 3551/udp` (open) or `sudo ufw deny 3551/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3551 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3551" dir=in action=allow protocol=UDP localport=3551`.
What applications and services use port 3551?
Port 3551/UDP is used by the apcupsd service. Specific uses depend on the software and configuration. Check our related tools section for more information.