Installation guide

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

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

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.