All ports

Port637/UDP

lanserver

Port

637

Protocol

UDP

Category

Well-Known

Service

lanserver

What is port 637?

Port 637/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the lanserver service.

lanserver

Useful commands

nmapnmap -p 637 -sV example.com
netcatnc -zv example.com 637
curlcurl -v http://example.com:637/
telnettelnet example.com 637
bash(echo > /dev/udp/example.com/637) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 637/udp
Deny
sudo ufw deny 637/udp
iptablesAllow
sudo iptables -A INPUT -p udp --dport 637 -j ACCEPT
Deny
sudo iptables -D INPUT -p udp --dport 637 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=637/udp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 637" dir=in action=allow protocol=UDP localport=637

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  • Outdated versions with vulnerabilities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 637/UDP?

Port 637/UDP is associated with the lanserver service. lanserver

Is it safe to expose port 637 to the Internet?

It depends on the service and configuration. Port 637 (lanserver) 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 637 is open?

You can use nmap: `nmap -p 637 -sV example.com`, netcat: `nc -zv example.com 637`, or the bash command: `(echo > /dev/udp/example.com/637) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 637 on my firewall?

On Linux with UFW: `sudo ufw allow 637/udp` (open) or `sudo ufw deny 637/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 637 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 637" dir=in action=allow protocol=UDP localport=637`.

What applications and services use port 637?

Port 637/UDP is used by the lanserver service. Specific uses depend on the software and configuration. Check our related tools section for more information.