All ports

Port187/UDP

aci

Port

187

Protocol

UDP

Category

Well-Known

Service

aci

What is port 187?

Port 187/UDP is a Well-Known port, assigned by IANA for widely recognized services. It is associated with the aci service.

Application Communication Interface

Useful commands

nmapnmap -p 187 -sV example.com
netcatnc -zv example.com 187
curlcurl -v http://example.com:187/
telnettelnet example.com 187
bash(echo > /dev/udp/example.com/187) 2>/dev/null

Firewall commands

UFWAllow
sudo ufw allow 187/udp
Deny
sudo ufw deny 187/udp
iptablesAllow
sudo iptables -A INPUT -p udp --dport 187 -j ACCEPT
Deny
sudo iptables -D INPUT -p udp --dport 187 -j ACCEPT
firewalldAllow
sudo firewall-cmd --permanent --add-port=187/udp
WindowsAllow
netsh advfirewall firewall add rule name="Open Port 187" dir=in action=allow protocol=UDP localport=187

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  • Outdated versions with vulnerabilities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 187/UDP?

Port 187/UDP is associated with the aci service. Application Communication Interface

Is it safe to expose port 187 to the Internet?

It depends on the service and configuration. Port 187 (aci) 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 187 is open?

You can use nmap: `nmap -p 187 -sV example.com`, netcat: `nc -zv example.com 187`, or the bash command: `(echo > /dev/udp/example.com/187) 2>/dev/null && echo "Open" || echo "Closed"`.

How do I open or close port 187 on my firewall?

On Linux with UFW: `sudo ufw allow 187/udp` (open) or `sudo ufw deny 187/udp` (close). With iptables: `sudo iptables -A INPUT -p udp --dport 187 -j ACCEPT`. On Windows: `netsh advfirewall firewall add rule name="Open Port 187" dir=in action=allow protocol=UDP localport=187`.

What applications and services use port 187?

Port 187/UDP is used by the aci service. Specific uses depend on the software and configuration. Check our related tools section for more information.

Related ports