Chapter 12. Network Scripts

165

The most common network

functions file is

network functions

, located

in the

/etc/sysconfig/network scripts/

directory. This file contains a variety of common IPv4

functions useful to many interface control scripts, such as contacting running programs that have

requested information about changes in an interface's status, setting host names, finding a gateway

device, seeing if a particular device is down or not, and adding a default route.

As the functions required for IPv6 interfaces are different than IPv4 interfaces, a

network functions ipv6

file exists specifically to hold this information. IPv6 support must be

enabled in the kernel in order to communicate via that protocol. A function is present in this file that

checks for the presence of IPv6 support. Additionally, functions that 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 can also be found in this file.

12.5. Additional Resources

More information concerning network scripts can be found in the following places.

  /usr/share/doc/initscripts  version /sysconfig.txt

  A comprehensive guide to

`

a

available options for network configuration files, including IPv6 options not covered in this chapter.

  /usr/share/doc/iproute  version /ip cref.ps

  This Postscript  file contains a

`

a

wealth of information about the

ip

command, which can be used to manipulate routing tables,

among other things. Use ghostview or kghostview to look at this file.