Red Hat Enterprise Linux makes use of several files that contain important common functions
used to bring interfaces up and down. Rather than forcing each interface
control file to contain these functions, they are grouped together in a
few files that are called upon when necessary.
The
/etc/sysconfig/network-scripts/network-functions
file contains the most commonly used IPv4 functions, which are useful to
many interface control scripts. These functions include contacting
running programs that have requested information about changes in an
interface's status, setting hostnames, finding a gateway device,
verifying whether or not if a particular device is down, and adding a
default route.
As the functions required for IPv6 interfaces are different than IPv4
interfaces, a
/etc/sysconfig/network-scripts/network-functions-ipv6
file exists specifically to hold this information. The functions in
this file configure and delete static IPv6 routes, create and remove
tunnels, add and remove IPv6 addresses to an interface, and test for the
existence of an IPv6 address on an interface.
