Windows Firewall Inbound Dynamic RPC

To create a rule that allows inbound network traffic to the RPC Endpoint Mapper service

1. On MBRSVR1, in Group Policy Management Editor for your server GPO, in the navigation pane, right-click Inbound Rules, and then click New rule.
   
2. On the Rule Type page, click Custom, and then click Next.
   
3. In the This program path text box, type %systemroot%\system32\svchost.exe.
   
4. Next to Services, click Customize.
   
5. Click Apply to this service, select Remote Procedure Call (RPC) with a short name of RpcSs, click OK, and then click Next.
   
6. On the warning about conflicting with Windows service-hardening rules, click Yes.
   
7. On the Protocol and Ports page, for Protocol type, select TCP.
   
8. For Local Port, select RPC Endpoint Mapper, and then click Next.
   
9. On the Scope page, click Next.
   
10. On the Action page, click Next.
    
11. On the Profile page, clear the Private and Public check boxes, and then click Next.
    
12. On the Name page, type Allow RPC Endpoint Mapper, and then click Finish.

Or:  netsh advfirewall firewall add rule name="Allow RPC" protocol=tcp service=rpcss dir=in action=allow profile=domain


 Source: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/cc732839(v=ws.10)