SAP troubleshooting · LessonBy Arjun, SAP Solution Architect · Published · Updated · SAP S/4HANA 2023 · all levels
SAP RFC errors
RFC errors break integration between SAP and other systems. This page covers diagnosing common RFC connection and call failures.
Quick answer
Use least-privilege service users and secure the gateway.
Key takeaways
- An interface, BAPI call or IDoc distribution fails with a communication or logon error.
- Start in SM59: run the connection and authorization test for the destination.
- Network/host, target unreachable (host/port/firewall).
- Watch out: connection failed and logon failed are different layers, and the message tells you which.
Symptom
An interface, BAPI call or IDoc distribution fails with a communication or logon error.
Start here: read the evidence
Start in SM59: run the connection and authorization test for the destination. Check the target system’s logs (SM21, ST22) and, for the interface, the relevant monitor (IDoc/qRFC). The error text usually distinguishes network, logon and authorization problems.
Likely causes, in order
- Network/host, target unreachable (host/port/firewall).
- Logon failed, wrong credentials or locked service user.
- Authorization, the RFC user lacks rights in the target.
- Gateway/security, blocked registered program or SNC issue.
How to fix it
- Run the SM59 connection and authorization tests.
- Verify host/port/network reachability to the target.
- Check the service user (valid, unlocked, right authorizations).
- Fix the destination or target-side authorization; re-test.
Preventing recurrence
Use least-privilege service users and secure the gateway. After a system copy, correct destinations that still point at the source. Monitor interfaces so RFC failures are caught before they back up.
Common pitfalls
- Guessing instead of reading the log/dump.
- Fixing the symptom, not the root cause.
- Changing several things at once.
Practice challenge
+0 XPStreak ×0
Question 1 of 3
Which statement is true of RFC errors?