<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <HTML ><HEAD ><TITLE >Port override syntax</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="FreeTDS User Guide" HREF="index.htm"><LINK REL="UP" TITLE="Install FreeTDS" HREF="install.htm"><LINK REL="PREVIOUS" TITLE="Environment variables" HREF="envvar.htm"><LINK REL="NEXT" TITLE="Confirm the installation" HREF="confirminstall.htm"><LINK REL="STYLESHEET" TYPE="text/css" HREF="userguide.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=utf-8"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" ><SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN > User Guide: A Guide to Installing, Configuring, and Running <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="envvar.htm" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 3. Install <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="confirminstall.htm" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="PORTOVERRIDE" >Port override syntax</A ></H1 ><P >The port to which to connect can be overridden using a <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN > extended syntax.</P ><P >A port may be appended to the servername in the form <TT CLASS="LITERAL" ><TT CLASS="REPLACEABLE" ><I >servername</I ></TT >:<TT CLASS="REPLACEABLE" ><I >port</I ></TT ></TT >. <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN > will attempt to connect to specified port. Please note <TT CLASS="REPLACEABLE" ><I >port</I ></TT > must be a number; a service name is not supported.</P ><P >If you specify <TT CLASS="LITERAL" ><TT CLASS="REPLACEABLE" ><I >servername</I ></TT >\<TT CLASS="REPLACEABLE" ><I >instance</I ></TT ></TT > as servername during login, <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN > will attempt to connect to specified instance. Only Microsoft SQL Server instances are supported. (This server feature was introduced with SQL Server 2000.)</P ><P >Note that other <TT CLASS="FILENAME" >freetds.conf</TT > properties still apply.</P ><P > For the technically curious: each SQL Server <I CLASS="FIRSTTERM" >instance</I > appears on the network as a server listening at a port. The old way — and it still works — is to designate each instance in <TT CLASS="FILENAME" >freetds.conf</TT > as a separate server. The new <SPAN CLASS="QUOTE" >"named instance"</SPAN > notation, if we can call it that, instead uses the server to discover the port. The library sends a UDP packet containing the instance name to the server at a <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >well known port</I ></SPAN >, port 1434. The server responds with a port number. <SPAN CLASS="PRODUCTNAME" >FreeTDS</SPAN > then uses that number to connect in the usual way.</P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="envvar.htm" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.htm" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="confirminstall.htm" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Environment variables</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="install.htm" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Confirm the installation</TD ></TR ></TABLE ></DIV ></BODY ></HTML >
