gai.conf(5) - phpMan

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 precendence
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 configura-
tion file:

label ::1/128 0
label ::/0 1
label 2002::/16 2
label ::/96 3
label ::ffff:0:0/96 4
precendence ::1/128 50
precendence ::/0 40
precendence 2002::/16 30
precendence ::/96 20
precendence ::ffff:0:0/96 10

FILES
/etc/gai.conf

AUTHOR
Ulrich Drepper <drepper redhat com>