How To Fix ESH_ADM_MSG154 - Error while opening an RFC connection. Cannot connect to &1 &2

SAP Error Message - Details

• Message type: E = Error

• Message class: ESH_ADM_MSG - ESH Administration and Monitoring Tool

• Message number: 154

• Message text: Error while opening an RFC connection. Cannot connect to &1 &2

What causes this issue?

The system cannot connect to server &1 and system number &2.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check if the values specified for the server name and the system number
are correct.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message ESH_ADM_MSG154 - Error while opening an RFC connection. Cannot connect to &1 &2 ?

  The SAP error message ESH_ADM_MSG154 indicates that there is an issue with establishing a Remote Function Call (RFC) connection to a specified system. The message typically includes placeholders for the target system's name and the connection type, which are represented as &1 and &2.
  Causes
  The error can be caused by several factors, including:
  
  Network Issues: There may be network connectivity problems between the SAP system and the target system.
  Incorrect Configuration: The RFC destination may not be configured correctly in the SAP system. This includes incorrect parameters such as the hostname, system number, client, user credentials, etc.
  Target System Down: The target SAP system may be down or not reachable.
  Firewall Restrictions: Firewalls or security settings may be blocking the connection.
  Authorization Issues: The user credentials used for the RFC connection may not have the necessary authorizations.
  SAP Gateway Issues: The SAP Gateway service may not be running on the target system.
  
  Solutions
  To resolve the error, you can follow these steps:
  
  
  Check Network Connectivity:
  
  Use tools like ping or telnet to check if the target system is reachable from the source system.
  
  
  
  Verify RFC Destination Configuration:
  
  Go to transaction SM59 in the SAP GUI.
  Locate the RFC destination that is causing the issue.
  Check the connection parameters (e.g., target host, system number, client, user, password).
  Test the connection using the "Test Connection" button.
  
  
  
  Check Target System Status:
  
  Ensure that the target SAP system is up and running.
  Check if the SAP services are active.
  
  
  
  Review Firewall Settings:
  
  Ensure that the necessary ports for RFC communication are open on both the source and target systems.
  
  
  
  Check User Authorizations:
  
  Verify that the user credentials used for the RFC connection have the necessary authorizations to connect to the target system.
  
  
  
  Check SAP Gateway:
  
  Ensure that the SAP Gateway service is running on the target system. You can check this using transaction SMGW.
  
  
  
  Review Logs:
  
  Check the system logs (transaction SM21) and the developer trace files (transaction ST11) for any additional error messages that may provide more context.
  
  
  
  Related Information
  
  
  Transaction Codes:
  
  SM59: Manage RFC Destinations
  SM21: System Log
  ST11: Developer Traces
  SMGW: SAP Gateway Monitor
  
  
  
  Documentation: Refer to SAP Help documentation for more details on RFC connections and troubleshooting.
  
  
  By following these steps, you should be able to identify and resolve the cause of the ESH_ADM_MSG154 error. If the issue persists, consider reaching out to your SAP Basis team or SAP support for further assistance.