All ports

Port502/UDP

mbap

Port

502

Protocol

UDP

Category

Well-Known

Service

mbap

What is port 502?

Port 502/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the mbap service.

Modbus Application Protocol

Useful commands

nmapnmap -p 502 -sV example.com
netcatnc -zv example.com 502
curlcurl -v http://example.com:502/
telnettelnet example.com 502
bash(echo > /dev/udp/example.com/502) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 502/udp
Deny
sudo ufw deny 502/udp
iptablesAllow
sudo iptables -A INPUT -p udp --dport 502 -j ACCEPT
Deny
sudo iptables -D INPUT -p udp --dport 502 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=502/udp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 502" dir=in action=allow protocol=UDP localport=502

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  • Outdated versions with vulnerabilities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 502/UDP?

Port 502/UDP is associated with the mbap service. Modbus Application Protocol

Is it safe to expose port 502 to the Internet?

It depends on the service and configuration. Port 502 (mbap) 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 502 is open?

You can use nmap: `nmap -p 502 -sV example.com`, netcat: `nc -zv example.com 502`, or the bash command: `(echo > /dev/udp/example.com/502) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 502 on my firewall?

On Linux with UFW: `sudo ufw allow 502/udp` (open) or `sudo ufw deny 502/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 502 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 502" dir=in action=allow protocol=UDP localport=502`.

What applications and services use port 502?

Port 502/UDP is used by the mbap service. Specific uses depend on the software and configuration. Check our related tools section for more information.

Related ports