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10.2.2. Network configuration files
The graphical helper tools edit a specific set of network configuration files, using a couple of basic commands. The exact names of the configuration files and their location in the file system is largely dependent on your Linux distribution and version. However, a couple of network configuration files are common on all UNIX systems:
10.2.2.1. /etc/hosts
The /etc/hosts file always contains the localhost IP address, 127.0.0.1, which is used for interprocess communication. Never remove this line! Sometimes contains addresses of additional hosts, which can be contacted without using an external naming service such as DNS (the Domain Name Server).
A sample hosts file for a small home network:
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost 192.168.52.10 tux.mylan.com tux
192.168.52.11 winxp.mylan.com winxp
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost.localdomain localhost 192.168.52.10 tux.mylan.com tux
192.168.52.11 winxp.mylan.com winxp
Read more in man hosts.
10.2.2.2. /etc/resolv.conf
The /etc/resolv.conf file configures access to a DNS server, see Section 10.3.7. This file contains your domain name and the name server(s) to contact:
search mylan.com nameserver 193.134.20.4
search mylan.com nameserver 193.134.20.4
Read more in the resolv.conf man page.
10.2.2.3. /etc/nsswitch.conf
The /etc/nsswitch.conf file defines the order in which to contact different name services. For Internet use, it is important that dns shows up in the "hosts" line:
[bob@tux ~] grep hosts /etc/nsswitch.conf
hosts: files dns
[bob@tux ~] grep hosts /etc/nsswitch.conf
hosts: files dns