All ports

Port1681/UDP

sd-elmd

Port

1681

Protocol

UDP

Category

Registered

Service

sd-elmd

What is port 1681?

Port 1681/UDP is a Registered port, registered with IANA for specific applications. It is associated with the sd-elmd service.

sd-elmd

Useful commands

nmapnmap -p 1681 -sV example.com
netcatnc -zv example.com 1681
curlcurl -v http://example.com:1681/
telnettelnet example.com 1681
bash(echo > /dev/udp/example.com/1681) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 1681/udp
Deny
sudo ufw deny 1681/udp
iptablesAllow
sudo iptables -A INPUT -p udp --dport 1681 -j ACCEPT
Deny
sudo iptables -D INPUT -p udp --dport 1681 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=1681/udp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 1681" dir=in action=allow protocol=UDP localport=1681

Security 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  • Outdated versions with vulnerabilities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 1681/UDP?

Port 1681/UDP is associated with the sd-elmd service. sd-elmd

Is it safe to expose port 1681 to the Internet?

It depends on the service and configuration. Port 1681 (sd-elmd) 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 1681 is open?

You can use nmap: `nmap -p 1681 -sV example.com`, netcat: `nc -zv example.com 1681`, or the bash command: `(echo > /dev/udp/example.com/1681) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 1681 on my firewall?

On Linux with UFW: `sudo ufw allow 1681/udp` (open) or `sudo ufw deny 1681/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 1681 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 1681" dir=in action=allow protocol=UDP localport=1681`.

What applications and services use port 1681?

Port 1681/UDP is used by the sd-elmd service. Specific uses depend on the software and configuration. Check our related tools section for more information.

Related ports