On the time when user finds some disturbance in system and get wrong hostname in SM51 with different name of in same server or system works with over workload data with wrong hostname. It is such too hard to get right hostname but the note can help to get that. The R/3 system is the mediator to communicate with TCP externally and it communicates between application and message server. User can use IP address because hostname can be resolved into IP address.
This process creates communication within same system or same machine. It is a very critical task for user of operates system with R/3 system. There are some following things need to be fulfilled for all host so that user can run system with R/3 system.