Create Inbound Rules to Support RPC

Applies to

  • Windows¬†10
  • Windows Server 2016

To allow inbound remote procedure call (RPC) network traffic, use the Windows Defender Firewall with Advanced Security node in the Group Policy Management console to create two firewall rules. The first rule allows incoming network packets on TCP port 135 to the RPC Endpoint Mapper service. The incoming traffic consists of requests to communicate with a specified network service. The RPC Endpoint Mapper replies with a dynamically-assigned port number that the client must use to communicate with the service. The second rule allows the network traffic that is sent to the dynamically-assigned port number. Using the two rules configured as described in this topic helps to protect your device by allowing network traffic only from devices that have received RPC dynamic port redirection and to only those TCP port numbers assigned by the RPC Endpoint Mapper.

Administrative credentials

To complete these procedures, you must be a member of the Domain Administrators group, or otherwise be delegated permissions to modify the GPOs.

This topic describes how to create rules that allow inbound RPC network traffic. For other inbound port rule types, see:

In this topic:

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

  1. Open the Group Policy Management Console to Windows Defender Firewall with Advanced Security.

  2. In the navigation pane, click Inbound Rules.

  3. Click Action, and then click New rule.

  4. On the Rule Type page of the New Inbound Rule Wizard, click Custom, and then click Next.

  5. On the Program page, click This Program Path, and then type %systemroot%\system32\svchost.exe.

  6. Click Customize.

  7. In the Customize Service Settings dialog box, click Apply to this service, select Remote Procedure Call (RPC) with a short name of RpcSs, click OK, and then click Next.

  8. On the warning about Windows service-hardening rules, click Yes.

  9. On the Protocol and Ports dialog box, for Protocol type, select TCP.

  10. For Local port, select RPC Endpoint Mapper, and then click Next.

  11. On the Scope page, you can specify that the rule applies only to network traffic to or from the IP addresses entered on this page. Configure as appropriate for your design, and then click Next.

  12. On the Action page, select Allow the connection, and then click Next.

  13. On the Profile page, select the network location types to which this rule applies, and then click Next.  

  14. On the Name page, type a name and description for your rule, and then click Finish.

To create a rule to allow inbound network traffic to RPC-enabled network services

  1. On the same GPO you edited in the preceding procedure, click Action, and then click New rule.

  2. On the Rule Type page of the New Inbound Rule Wizard, click Custom, and then click Next.

  3. On the Program page, click This Program Path, and then type the path to the executable file that hosts the network service. Click Customize.

  4. In the Customize Service Settings dialog box, click Apply to this service, and then select the service that you want to allow. If the service does not appear in the list, then click Apply to service with this service short name, and then type the short name of the service in the text box.

  5. Click OK, and then click Next.

  6. On the Protocol and Ports dialog box, for Protocol type, select TCP.

  7. For Local port, select RPC Dynamic Ports, and then click Next.

  8. On the Scope page, you can specify that the rule applies only to network traffic to or from the IP addresses entered on this page. Configure as appropriate for your design, and then click Next.

  9. On the Action page, select Allow the connection, and then click Next.

  10. On the Profile page, select the network location types to which this rule applies, and then click Next.

  11. On the Name page, type a name and description for your rule, and then click Finish.