gai.conf(5)

1gai.conf(5)                   File Formats Manual                  gai.conf(5)
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NAME

6       gai.conf - getaddrinfo(3) configuration file
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DESCRIPTION

10       A  call  to getaddrinfo(3) might return multiple answers.  According to
11       RFC 3484 these answers must be sorted so that the answer with the high‐
12       est  success rate is first in the list.  The RFC provides and algorithm
13       for the sorting.  The static rules are  not  always  adequate,  though.
14       For  this  reason  the RFC also requires that system administrators get
15       the chance to dynamically change the sorting.  For the glibc  implemen‐
16       tation this can be achieved with the /etc/gai.conf file.
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18       Each  line  in  the  configuration  file  consists of a keyword and its
19       parameters.  White spaces in any place  are  ignored.   Lines  starting
20       with `#' are comments and are ignored.
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22       The keywords currently recognized are:
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24       label netmask precedence
25              The value is added to the label table used in the RFC 3484 sort‐
26              ing.  If any label definition is present  in  the  configuration
27              file  is  present  the default table is not used.  All the label
28              definitions of the default table which are to be maintained have
29              to be duplicated.  Following the keyword the line has to contain
30              a network mask and a label value.
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33       precedence netmask precedence
34              This  keyword is similar to label but instead the value is added
35              to  the  precedence table as specified in RFC 3484.  Once again,
36              the presence of a single precedence line  in  the  configuration
37              file causes the default table to not be used.
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40       reload <yes|no>
41              This  keyword  control whether a process checks whether the con‐
42              figuration file has been changes since  the  last  time  it  was
43              read.   If  the  value is `yes' the file is re-read.  This might
44              cause problems in multi-threaded applications and is generally a
45              bad idea.  The default is `no'.
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EXAMPLE

50       The  default  table  according  to RFC 3484 would be specified with the
51       following configuration file:
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53       label  ::1/128       0
54       label  ::/0          1
55       label  2002::/16     2
56       label ::/96          3
57       label ::ffff:0:0/96  4
58       precedence  ::1/128       50
59       precedence  ::/0          40
60       precedence  2002::/16     30
61       precedence ::/96          20
62       precedence ::ffff:0:0/96  10
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FILES

67       /etc/gai.conf
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AUTHOR

71       Ulrich Drepper <drepper@redhat.com>
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NAME

DESCRIPTION

EXAMPLE

FILES

AUTHOR

SEE ALSO