To communicate with external hardware via Ethernet, MATLAB (or any standalone applications generated with MATLAB Compiler) must be allowed to communicate on all types of networks through Windows Defender Firewall. The steps are as follows:
- Step 1: Configure the PC Ethernet interface as 'Private'
- Step 2: Create general inbound and outbound firewall rules for MATLAB
- Step 3: Add a specific inbound rule for UDP traffic
Important notes:
- Perform the steps below in collaboration with your IT system administrator.
- You must repeat the procedure below for every installed version of MATLAB and every standalone application that you intend to use with external hardware. The same applies if you upgrade MATLAB to a newer version at any point in the future.
- The steps below may also have to be repeated after any company-wide IT rollouts or Windows Updates, as firewall settings may be reset as part of this.
- When allowing access for a standalone SLRT app created with MATLAB Compiler, make sure that the application (e.g. "slrt_app.exe") is selected to your firewall rules rather than "matlab.exe".
Step 1: Configure the PC Ethernet Interface as 'Private'
To ensure smooth host-target communication, we recommend configuring the host PC Ethernet interface connected to the hardware as 'Private'. Windows classifies all Ethernet connections as 'Public' by default, which can disrupt communication due to the security restrictions associated with this network type. Additionally, users may lack the necessary permissions to set any firewall rules for 'Public' networks. Refer to our documentation for detailed instructions:
Step 2: Create general inbound and outbound firewall rules for MATLAB
Create one Inbound Rule and one Outbound Rule in the Advanced Windows Defender Firewall settings as follows:
1) Find Windows Defender Firewall with Advanced Security by using the Windows search.
2) Select Inbound Rules and New Rule.
3) For the Rule Type, select Program, and click Next.
4) Select This program path and find the MATLAB release that you are using. Make sure to select matlab.exe from the bin folder (<matlabroot>\bin\matlab.exe): 
5) For the Action, select Allow the connection, and click Next.
6) For the Profile, select the Domain, Private, and Public checkboxes. If the 'Public' checkbox is grayed out, you must configure the network interface as 'Private' as per Step 1 above). Click Next.
7) For Name, provide a Name for this inbound rule (for example, MATLAB R2020b inbound), and click Finish.
8) Select Outbound Rules and click New Rule.
9) Repeat steps 3 through 7 for the custom outbound rule.
If any of the above options are not available due to IT policy, please contact your IT helpdesk to verify your firewall rules.
Step 3: Add a specific inbound rule for UDP traffic
Especially on Windows 11 systems, incoming UDP traffic may be incorrectly classified as malicious and blocked, even if a general firewall rule permits incoming communication. To ensure proper connectivity, it may be necessary to create an additional explicit rule to allow incoming UDP traffic.
To use Speedgoat with MATLAB R2020b through R2025b, please follow this MATLAB Answer to add a third firewall rule to unblock the UDP ports used by the FastDDS/RTPS protocol.
For other hardware, this step is only necessary if you use UDP Send blocks in your Simulink model to exchange data between the hardware and the host computer. In that case, unblock the ports as specified in your UDP blocks.
Summary
You should now have a set of 3 firewall rules. Important: You must have this set of rules for every installed version of MATLAB and every standalone application that you intend to use with external hardware.
Further Troubleshooting
If the above instructions don't help resolve the communication issues with your Speedgoat hardware, refer to the following MATLAB Answers post for further troubleshooting steps:
