All ports
Port3511/UDP
webmail-2Port
3511
Protocol
UDP
Category
Registered
Service
webmail-2
What is port 3511?
Port 3511/UDP is a Registered port, registered with IANA for specific applications. It is associated with the webmail-2 service.
WebMail/2
Useful commands
nmapnmap -p 3511 -sV example.comnetcatnc -zv example.com 3511curlcurl -v http://example.com:3511/telnettelnet example.com 3511bash(echo > /dev/udp/example.com/3511) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3511/udpDeny
sudo ufw deny 3511/udpiptablesAllow
sudo iptables -A INPUT -p udp --dport 3511 -j ACCEPTDeny
sudo iptables -D INPUT -p udp --dport 3511 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3511/udpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3511" dir=in action=allow protocol=UDP localport=3511Security Risks
- Open relay used for spam
- Email spoofing
- Brute force attacks against email accounts
- Information disclosure in email headers
Frequently Asked Questions
What service runs on port 3511/UDP?
Port 3511/UDP is associated with the webmail-2 service. WebMail/2
Is it safe to expose port 3511 to the Internet?
It depends on the service and configuration. Port 3511 (webmail-2) 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 3511 is open?
You can use nmap: `nmap -p 3511 -sV example.com`, netcat: `nc -zv example.com 3511`, or the bash command: `(echo > /dev/udp/example.com/3511) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3511 on my firewall?
On Linux with UFW: `sudo ufw allow 3511/udp` (open) or `sudo ufw deny 3511/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 3511 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3511" dir=in action=allow protocol=UDP localport=3511`.
What applications and services use port 3511?
Port 3511/UDP is used by the webmail-2 service. Specific uses depend on the software and configuration. Check our related tools section for more information.