Interfaces configuration file

This file usually has at least two lines, one line specifying the IP address of a DNS server or name server and the other specifying the search domain. The following example shows three name servers and the search domain:. This file specifies global network settings. For example, you can specify the default gateway in this file:.

This file is the system databases and name service switch configuration file. It provides sources for common configuration databases and name resolution mechanisms.

However, it is also possible to manually edit the configuration files for a given network interface. Below is a listing of the configurable parameters in an Ethernet interface configuration file:. This configuration method is used so that multiple bonding devices can have different configurations. See Where to specify bonding module parameters for more information. This directive is deprecated, as the value is calculated automatically with ipcalc.

This is the default value. An IPv6 link-local address will still be assigned by default. For example, if you wanted to force Mb, full duplex:. Custom initscripts run outside of the network init script lead to unpredictable results during a post-boot network service restart. Changing speed or duplex settings almost always requires disabling auto-negotiation with the autoneg off option. This option needs to be stated first, as the option entries are order-dependent.

Interface Configuration Files. Interface configuration files control the software interfaces for individual network devices. As the system boots, it uses these files to determine what interfaces to bring up and how to configure them. Ethernet Interfaces. One of the most common interface files is ifcfg-eth0 , which controls the first Ethernet network interface card or NIC in the system.

Because each device has its own configuration file, an administrator can control how each interface functions individually.