Chapter 1. Network Interfaces
Under Fedora, all network communications occur between configured software interfaces and physical networking devices connected to the system.
The configuration files for network interfaces are located in the /etc/sysconfig/network-scripts/
directory. The scripts used to activate and deactivate these network interfaces are also located here. Although the number and type of interface files can differ from system to system, there are three categories of files that exist in this directory:
Interface configuration files
Interface control scripts
Network function files
The files in each of these categories work together to enable various network devices.
This chapter explores the relationship between these files and how they are used.
1.1. Network Configuration Files
The primary network configuration files are as follows:
-
/etc/hosts
The main purpose of this file is to resolve host names that cannot be resolved any other way. It can also be used to resolve host names on small networks with no DNS
server. Regardless of the type of network the computer is on, this file should contain a line specifying the IP
address of the loopback device (127.0.0.1
) as localhost.localdomain
. For more information, see the hosts(5)
man page.
-
/etc/hostname
There are three separate classes of host names in use on a given system. The pretty host name is the high level host name often presented to users by their desktop environment or shell. The static host name is used by the kernel at boot, and is usually the system's fully qualified domain name. A system may also have a transient host name assigned by a dhcp server. The hostnamectl tool is provided for administering these host names. For more information on host names, see man hostname(5)
and man hostnamectl(1)
.
-
/etc/resolv.conf
This file specifies the IP
addresses of DNS
servers and the search domain. Unless configured to do otherwise, the network initialization scripts populate this file. For more information about this file, refer to the resolv.conf(5)
man page.
-
/etc/sysconfig/network
This file specifies routing and host information for all network interfaces. It is used to contain directives which are to have global effect and not to be interface specific. For more information about this file and the directives it accepts, see
Section 3.1.13, “/etc/sysconfig/network”.
-
/etc/sysconfig/network-scripts/ifcfg-interface-name
For each network interface, there is a corresponding interface configuration script. Each of these files provide information specific to a particular network interface. See
Section 1.2, “Interface Configuration Files” for more information on this type of file and the directives it accepts.
Network interface names may be different on different hardware types. See the Fedora Networking Guide for more information on device naming.