How To Fix SCLNT_HTTP411 - Connection refused by server (ICM_HTTP_CONNECTION_REFUSED)

SAP Error Message - Details

• Message type: E = Error

• Message class: SCLNT_HTTP - Messages for HTTP Client for Respective Error Code

• Message number: 411

• Message text: Connection refused by server (ICM_HTTP_CONNECTION_REFUSED)

What causes this issue?

The server has rejected the connection.

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?

Ensure that the server is reachable at the specified port number. A
possible cause for this is that the specified server was stopped
temporarily. In this case, try the connection again at a later point or
contact the server administrator.

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 SCLNT_HTTP411 - Connection refused by server (ICM_HTTP_CONNECTION_REFUSED) ?

  The SAP error message SCLNT_HTTP411 Connection refused by server (ICM_HTTP_CONNECTION_REFUSED) typically indicates that the Internet Communication Manager (ICM) in the SAP system is unable to establish a connection to the specified server. This can occur for several reasons, and understanding the cause is essential for troubleshooting and resolving the issue.
  Causes
  
  
  Server Not Running: The target server or service you are trying to connect to may not be running or may have crashed.
  
  
  Network Issues: There could be network connectivity issues between the SAP system and the target server, such as firewall rules blocking the connection.
  
  
  Incorrect Configuration: The configuration settings in the SAP system (like the HTTP destination) may be incorrect, leading to connection attempts to the wrong server or port.
  
  
  Port Issues: The port specified in the connection settings may not be open or may be blocked by a firewall.
  
  
  Service Unavailable: The service you are trying to reach may be temporarily unavailable or overloaded.
  
  
  SSL/TLS Issues: If you are trying to connect over HTTPS, there may be issues with SSL/TLS certificates or configurations.
  
  
  Solutions
  
  
  Check Server Status: Ensure that the target server is up and running. You can do this by trying to access the server directly through a web browser or using tools like ping or telnet.
  
  
  Verify Network Connectivity: Check for any network issues that might be preventing the connection. This includes checking firewalls, routers, and network configurations.
  
  
  Review Configuration Settings: Go to the SAP system and check the configuration settings for the HTTP destination (transaction code SM59). Ensure that the target host and port are correctly specified.
  
  
  Check Port Availability: Use tools like netstat or telnet to check if the specified port is open and listening on the target server.
  
  
  Service Health: If the service is temporarily unavailable, you may need to wait and try again later. Check the service logs for any errors or issues.
  
  
  SSL/TLS Configuration: If using HTTPS, ensure that the SSL/TLS certificates are valid and properly configured. You may need to import the server's certificate into the SAP system's trust store.
  
  
  Review ICM Logs: Check the ICM logs for more detailed error messages. You can find these logs in the transaction SMICM under the "Log File" section.
  
  
  Restart ICM: If you suspect that the ICM is in a bad state, you can try restarting it. This can sometimes resolve transient issues.
  
  
  Related Information
  
  
  Transaction Codes:
  
  SM59: To manage HTTP connections.
  SMICM: To monitor and manage the Internet Communication Manager.
  
  
  
  SAP Notes: Check SAP Notes related to ICM and HTTP connection issues for any known bugs or patches.
  
  
  Documentation: Refer to the official SAP documentation for detailed information on configuring and troubleshooting ICM.
  
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.