All ports
Port3821/TCP
pmcpPort
3821
Protocol
TCP
Category
Registered
Service
pmcp
What is port 3821?
Port 3821/TCP is a Registered port, registered with IANA for specific applications. It is associated with the pmcp service.
ATSC PMCP Standard
Useful commands
nmapnmap -p 3821 -sV example.comnetcatnc -zv example.com 3821curlcurl -v http://example.com:3821/telnettelnet example.com 3821bash(echo > /dev/tcp/example.com/3821) 2>/dev/nullFirewall commands
UFWAllow
sudo ufw allow 3821/tcpDeny
sudo ufw deny 3821/tcpiptablesAllow
sudo iptables -A INPUT -p tcp --dport 3821 -j ACCEPTDeny
sudo iptables -D INPUT -p tcp --dport 3821 -j ACCEPTfirewalldAllow
sudo firewall-cmd --permanent --add-port=3821/tcpWindowsAllow
netsh advfirewall firewall add rule name="Open Port 3821" dir=in action=allow protocol=TCP localport=3821Security 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- Outdated versions with vulnerabilities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 3821/TCP?
Port 3821/TCP is associated with the pmcp service. ATSC PMCP Standard
Is it safe to expose port 3821 to the Internet?
It depends on the service and configuration. Port 3821 (pmcp) 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 3821 is open?
You can use nmap: `nmap -p 3821 -sV example.com`, netcat: `nc -zv example.com 3821`, or the bash command: `(echo > /dev/tcp/example.com/3821) 2>/dev/null && echo "Open" || echo "Closed"`.
How do I open or close port 3821 on my firewall?
On Linux with UFW: `sudo ufw allow 3821/tcp` (open) or `sudo ufw deny 3821/tcp` (close). With iptables: `sudo iptables -A INPUT -p tcp --dport 3821 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 3821" dir=in action=allow protocol=TCP localport=3821`.
What applications and services use port 3821?
Port 3821/TCP is used by the pmcp service. Specific uses depend on the software and configuration. Check our related tools section for more information.