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SM59, RFC destination, RFC error Interview Questions and Answers

Updated May 19, 2018

FAQ, Q+A, SM59, RFC destination, RFC error 

Q: Can I also change internal connections?

A: No, the internal connections are set automatically by the system and must not be changed.

Q: Which tests are available in SM59 to check an RFC connection?

A: Open the RFC connection, use the menu option 'Test' to access a connection and authorization test and a test of the available application servers.

Q: The communication to an RFC destination contains errors, connections are terminated or other problems occur, how I can implement tests?

A: First of all, test access using the connection test of the RFC destination in SM59.Then execute an authorization test to check whether the user has the necessary authorization.

Q: One or both tests fail, how can I proceed?

A: In the connection options, set the trace indicator so that an extended trace is written. Run the test again. The trace is written to a development trace file 'dev_rfc', which you can view using the transaction ST11 (TA:SM59 - RFC - Trace). The file is numbered based on the work process used. Notes 176277 and 532918 describe other options for writing an RFC trace, and also describe the different communication partners.

Q: A termination occurs during the authorization test. What should I do?

A: Use the termination code or keywords to search for SAPNET-R/3 Frontend notes.If you are not sure which authorizations your user needs, create an authorization trace using transaction ST01.

Q: The connection test fails. What are the possible causes?

A: Login data is incorrect  a login screen automatically appears for a dialog user. The target machine is not accessible  are the host name, IP address, and path correct?
Ensure that the target machine can be accessed using operating system tools (Ping) and that the host name is resolved correctly.
   The 'hostname' command must issue the correct host name, 'Ping' on these host names must deliver the correct IP address. The command 'nslookup <IP address>' must resolve back the IP address correctly on the host names (Reverse Lookup).
   If the connection is to be set up to a registered RFC program, check whether the program is still registered on the gateway, and that you address the correct gateway.
   If you do not specify gateway, the local gateway is used by default. To reach an RFC server program from different application servers, for example, you must specify in the RFC option the gateway at which the program is registered.

Q: Which trace files can I also use in problem analysis?

A: The developer trace 'dev_w' of the corresponding work process and the gateway trace 'dev_rd' may also contain key supplementary information on the reason for the termination.
   If an external program is involved, files of the type 'rfc.trc' or 'dev_rfc' may be written. They appear in the directory from which the external program was started. This trace is activated by setting the environment variables 'RFC_TRACE' to 1 ('set environment' or using 'saprfc.ini') or by setting the trace parameter for the RFC API functions 'RFCOpen' or 'RFCOpenEx' to open the connection.

Q: Are there other options for testing the RFC connection, for example at operating system level?

A: Use the 'Sapinfo' tool, to test an RFC connection at OS level.
   A simplified call without an intermediate SAProuter is, for example:
   'sapinfo -3 -h<Server host> -s<Instance number> '
   A call that takes account of intermediate SAProuters is:
   'sapinfo -3 -g<Route string> -h<Server host> -s<Instance number> '
   You can do this as a simple means of determining whether it is actually possible to reach an R/3 System using RFC from the calling machine (RFC client).
   To do this, you need the RFC Software Development Kit (RFCSDK), that is on the 'Presentation CD' (CD1 or CD2, depending on whether you use Unix or Windows as a platform).

Q: The connection test works, however a remote logon does not. What are the possible causes?

A: Check the logon data and the user. Ensure that the type 'Dialog' is used (SU01 - logon data).
Check whether network components prevent logon or confirmation, for example, a router or a firewall.
   A remote logon from SM59 using a Saprouter is not supported by SAP.

Q: The connection to an external, registered RFC server only functions sporadically.

A: Several hosts are in a system, the external server is registered at a gateway. The connection test only works from the PC which has a (local) gateway to which the external server is registered.
   Problem: No gateway options are maintained for the destination.
   Solution: Maintain the gateway host, and service parameters in the RFC options.
   The parameters are identical with the -x and -g parameters during registration.
   They can be determined from the host name in transaction SM51 or using the Gateway Monitor (transaction SMGW) parameters.