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+.\" Copyright (C) 2006 Red Hat, Inc. All rights reserved.
+.\" Author: Ulrich Drepper <drepper@redhat.com>
+.\"
+.\" SPDX-License-Identifier: GPL-2.0-only
+.\"
+.TH gai.conf 5 2024-05-02 "Linux man-pages (unreleased)"
+.SH NAME
+gai.conf \- getaddrinfo(3) configuration file
+.SH DESCRIPTION
+A call to
+.BR getaddrinfo (3)
+might return multiple answers.
+According to RFC\ 3484 these answers must be sorted so that
+the answer with the highest success rate is first in the list.
+The RFC provides an algorithm for the sorting.
+The static rules are not always adequate, though.
+For this reason,
+the RFC also requires that system administrators should have the possibility
+to dynamically change the sorting.
+For the glibc implementation, this can be achieved with the
+.I /etc/gai.conf
+file.
+.P
+Each line in the configuration file consists of a keyword and its parameters.
+White spaces in any place are ignored.
+Lines starting with \[aq]#\[aq] are comments and are ignored.
+.P
+The keywords currently recognized are:
+.TP
+\fBlabel\fR \fInetmask\fR \fIprecedence\fR
+The value is added to the label table used in the RFC\ 3484 sorting.
+If any \fBlabel\fR definition is present in the configuration file,
+the default table is not used.
+All the label definitions
+of the default table which are to be maintained have to be duplicated.
+Following the keyword,
+the line has to contain a network mask and a precedence value.
+.TP
+\fBprecedence\fR \fInetmask\fR \fIprecedence\fR
+This keyword is similar to \fBlabel\fR, but instead the value is added
+to the precedence table as specified in RFC\ 3484.
+Once again, the
+presence of a single \fBprecedence\fR line in the configuration file
+causes the default table to not be used.
+.TP
+\fBreload\fR <\fByes\fR|\fBno\fR>
+This keyword controls whether a process checks whether the configuration
+file has been changed since the last time it was read.
+If the value is
+"\fByes\fR", the file is reread.
+This might cause problems in multithreaded
+applications and is generally a bad idea.
+The default is "\fBno\fR".
+.TP
+\fBscopev4\fR \fImask\fR \fIvalue\fR
+Add another rule to the RFC\ 3484 scope table for IPv4 address.
+By default, the scope IDs described in section 3.2 in RFC\ 3438 are used.
+Changing these defaults should hardly ever be necessary.
+.SH FILES
+\fI/etc/gai.conf\fR
+.SH VERSIONS
+The
+.I gai.conf
+.\" Added in 2006
+file is supported since glibc 2.5.
+.SH EXAMPLES
+The default table according to RFC\ 3484 would be specified with the
+following configuration file:
+.P
+.in +4n
+.EX
+label  ::1/128       0
+label  ::/0          1
+label  2002::/16     2
+label ::/96          3
+label ::ffff:0:0/96  4
+precedence  ::1/128       50
+precedence  ::/0          40
+precedence  2002::/16     30
+precedence ::/96          20
+precedence ::ffff:0:0/96  10
+.EE
+.in
+.\" .SH AUTHOR
+.\" Ulrich Drepper <drepper@redhat.com>
+.\"
+.SH SEE ALSO
+.BR getaddrinfo (3),
+RFC\ 3484