SAP usually displays the error RFC callback call rejected by whitelist when a request to make a Remote Function Call (RFC) callback is denied because of whitelist limitations,
Causes of the Error
- RFC Whitelisting Configuration: A security feature of SAP systems limits which RFC calls are made through or from external systems. The callback will be declined if the RFC destination is not whitelisted.
- Missing RFC Whitelist Entries: The SAP system will reject those calls if it is not set up correctly to accept certain RFC callback destinations.
- Security Policies: In order to prevent malicious or unauthorized access, your SAP system may be configured with a stringent security policy that prohibits RFC callbacks.
How to Resolve the Error?
1. Check the Whitelist Configuration:
- Navigate to t-code SM59 to review and configure RFC destinations.
- Make sure the system you are attempting to connect to has been defined correctly and is reachable.
- Verify whether the required RFC callback is on the whitelist.
2. Adjust Whitelist Settings:
Use t-code SMGW (Gateway Monitor) or t-code RZ11 (Parameter Maintenance) to adjust the following parameters:
- gw/acl_mode: Controls whether the access control list (ACL) feature is enabled. To enable whitelist checks, set this parameter to 1.
- gw/reg_no_conn_info: If set to 1 will require RFC callbacks to have entries in the whitelist.
- Make sure the reg_info and sec_info files whitelist entries are set up properly to permit the necessary RFC callback requests.
3. Maintain Security Settings:
Execute t-code SMGW to check the current settings of the RFC Gateway and ensure that all necessary entries are allowed.
In order to adjust the entries in reginfo and secinfo files on the application server to whitelist the required callback connections.
4. Consult SAP Notes:
To find out more information or patches for your particular SAP version, look for any pertinent SAP Notes.
5. System Restart:
It might be necessary to restart the SAP system or the gateway after making modifications to the reginfo and secinfo files or the gateway's parameters.