%META:TOPICPARENT{name="PreRequisitesINF"}%
=Identify the Informix startup mode (i.e., sockets or shared memory) =

%TOC%

==Unix Database Servers==

# Log in to your Unix database server as the Informix user.
# Set the Informix environment, if not automatically set by the login.
# Execute this command: 
{{{
echo $INFORMIXSERVER
}}}
# Execute this command: 
{{{
cat $INFORMIXDIR/etc/sqlhosts
}}}
# Look for the line that begins with the {{{$INFORMIXSERVER}}} value, and note the value that appears in the second column.
#* If this value is {{{onsoctcp}}}, {{{ontlitcp}}}, or anything else containing {{{tcp}}}, this {{{$INFORMIXSERVER}}}  will accept sockets-based connections. 
#* If this value is {{{onipcshm}}}, or anything else containing {{{shm}}}, this {{{$INFORMIXSERVER}}}  will not accept sockets-based connections; it will only accept shared-memory connections.  

==Windows Database Servers==

# Login to your Windows database server.
# Open an MS-DOS command prompt.
# Run this command: 
{{{
regedit
}}}
# Drill down to 
{{{
HKEY_LOCAL_MACHINE\
   SOFTWARE\
      INFORMIX\
         SQLHOSTS
}}}
# Look for the value passed to {{{PROTOCOL}}}.
#* If this value is {{{onsoctcp}}}, {{{ontlitcp}}}, or anything else containing {{{tcp}}}, this {{{$INFORMIXSERVER}}}  will accept sockets-based connections. 
#* If this value is {{{onipcshm}}}, or anything else containing {{{shm}}}, this {{{$INFORMIXSERVER}}}  will not accept sockets-based connections; it will only accept shared-memory connections.

== Ramifications ==

* Sockets-based (TCP/IP) connections are supported by Enterprise Edition, Lite Edition, and Express Edition, regardless of whether the OpenLink components are running on the Informix host or elsewhere.

* Shared-memory connections are supported only when our Enterprise Edition server-side components (Request Broker and Database Agent) or our Lite Edition client-side components are running on the Informix server host.  Shared-memory connections are not supported by our Express Edition, nor by our Lite Edition when not running on the Informix server host.