The services.sde file
The services.sde file in the etc directory of SDEHOME contains the service name and the unique Transmission Control Protocol/Internet Protocol (TCP/IP) port number on which the ArcSDE service (also called an application server) accepts connection requests. The services.sde file must be configured before ArcSDE can be started.
The port number in this file is also assigned to each user or gsrvr process that the ArcSDE service initiates. The port number listed in the services.sde file does not designate operating system port use. It is included in services.sde by convention as a reminder of the port number assigned to the service name in the operating system's services file. Esri has registered the default esri_sde service name and 5151 TCP/IP port number with the Information Sciences Institute, Internet Assigned Numbers Authority.
The default services.sde file created during the installation process contains the following:
# ESRI ArcSDE Remote Protocol # #esri_sde 5151/tcp
If you are going to use the default service name and port number, you need to remove the comment mark (#) from in front of esri_sde 5151/tcp. If you are going to use different or additional service names and port numbers, type them on the next line without a comment mark (#).
On UNIX or Linux systems, the services.sde file is always used if you are using an ArcSDE service. However, on Windows systems, the services.sde file is used only when the service is started from the MS-DOS prompt using the sdemon command. When the ArcSDE service is started with the sdemon command, the system services file is searched for a service name that matches the service name in the services.sde file. When a match is found, ArcSDE starts the giomgr process and listens for user connection requests on the TCP/IP port number assigned to the service name. If a match is not found, ArcSDE returns an error message (on UNIX/Linux systems) or logs an error in the sde_<service_name>.log file (on Windows).
If the service is started from the Windows service panel, ArcSDE looks for the service name in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\ESRI\ArcInfo\ArcSDE\ArcSDE for <dbms>\<service name>.