All ports
Port401/UDP
upsPort
401
Protocol
UDP
Category
Well-Known
Service
ups
What is port 401?
Port 401/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the ups service.
Uninterruptible Power Supply
Useful commands
nmapnmap -p 401 -sV example.comnetcatnc -zv example.com 401curlcurl -v http://example.com:401/telnettelnet example.com 401bash(echo > /dev/udp/example.com/401) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 401/udpDeny
sudo ufw deny 401/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 401 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 401 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=401/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 401" dir=in action=allow protocol=UDP localport=401Security 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- Outdated versions with vulnerabilities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 401/UDP?
Port 401/UDP is associated with the ups service. Uninterruptible Power Supply
Is it safe to expose port 401 to the Internet?
It depends on the service and configuration. Port 401 (ups) 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 401 is open?
You can use nmap: `nmap -p 401 -sV example.com`, netcat: `nc -zv example.com 401`, or the bash command: `(echo > /dev/udp/example.com/401) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 401 on my firewall?
On Linux with UFW: `sudo ufw allow 401/udp` (open) or `sudo ufw deny 401/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 401 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 401" dir=in action=allow protocol=UDP localport=401`.
What applications and services use port 401?
Port 401/UDP is used by the ups service. Specific uses depend on the software and configuration. Check our related tools section for more information.