gai.conf(5)                                                                                                          gai.conf(5)



NAME
       gai.conf - getaddrinfo(3) configuration file


DESCRIPTION
       A  call  to 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 and algorithm for the sorting.   The  static
       rules  are  not always adequate, though.  For this reason the RFC also requires that system administrators get the chance
       to dynamically change the sorting.  For the glibc implementation this can be achieved with the /etc/gai.conf file.

       Each line in the configuration file consists of a keyword and its parameters.  White spaces in  any  place  are  ignored.
       Lines starting with `#' are comments and are ignored.

       The keywords currently recognized are:

       label netmask precedence
              The  value  is  added  to the label table used in the RFC 3484 sorting.  If any label definition is present in the
              configuration file is present 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
              label value.


       precedence netmask precedence
              This  keyword is similar to label but instead the value is added to the precedence table as specified in RFC 3484.
              Once  again, the presence of a single precedence line in the configuration file causes the default table to not be
              used.


       reload <yes|no>
              This keyword control whether a process checks whether the configuration file has been changes since the last  time
              it was read.  If the value is `yes' the file is re-read.  This might cause problems in multi-threaded applications
              and is generally a bad idea.  The default is `no'.



EXAMPLE
       The default table according to RFC 3484 would be specified with the following configuration file:

       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



FILES
       /etc/gai.conf


AUTHOR
       Ulrich Drepper <drepperATredhat.com>


SEE ALSO
       getaddrinfo(3), RFC 3484



gai.conf                                                    May 2006                                                 gai.conf(5)