1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
---|
2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
---|
3 | "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
|
---|
4 | <!ENTITY % general-entities SYSTEM "../general.ent">
|
---|
5 | %general-entities;
|
---|
6 | ]>
|
---|
7 |
|
---|
8 | <sect1 id="ch-scripts-network">
|
---|
9 | <?dbhtml filename="network.html"?>
|
---|
10 |
|
---|
11 | <title>General Network Configuration</title>
|
---|
12 |
|
---|
13 | <indexterm zone="ch-scripts-network">
|
---|
14 | <primary sortas="d-network">network</primary>
|
---|
15 | <secondary>configuring</secondary></indexterm>
|
---|
16 |
|
---|
17 | <para>This section only applies if a network card is to be
|
---|
18 | configured.</para>
|
---|
19 |
|
---|
20 | <sect2>
|
---|
21 | <title>Network Interface Configuration Files</title>
|
---|
22 |
|
---|
23 | <para>Starting with version 209, systemd ships a network configuration
|
---|
24 | daemon called <command>systemd-networkd</command> which can be used for
|
---|
25 | basic network configuration.</para>
|
---|
26 |
|
---|
27 | <para>Configuration files for <command>systemd-networkd</command> can be
|
---|
28 | placed in <filename class="directory">/usr/lib/systemd/network</filename>
|
---|
29 | or <filename class="directory">/etc/systemd/network</filename>. Note that
|
---|
30 | files in <filename class="directory">/etc/systemd/network</filename> have
|
---|
31 | higher priority than the ones in
|
---|
32 | <filename class="directory">/usr/lib/systemd/network</filename>.</para>
|
---|
33 |
|
---|
34 | <para>There are three types of configuration files:
|
---|
35 | <filename class="extension">.link</filename>,
|
---|
36 | <filename class="extension">.netdev</filename> and
|
---|
37 | <filename class="extension">.network</filename> files. For detailed
|
---|
38 | explanation about contents of the mentioned
|
---|
39 | configuration files, consult <filename>systemd-link(5)</filename>,
|
---|
40 | <filename>systemd-netdev(5)</filename> and
|
---|
41 | <filename>systemd-network(5)</filename> manual pages.</para>
|
---|
42 |
|
---|
43 | <note><para>Udev may assign network card interface names based
|
---|
44 | on system physical characteristics such as enp2s1. If you are
|
---|
45 | not sure what your interface name is, you can always run
|
---|
46 | <command>ip link</command> after you have booted your system.
|
---|
47 | </para></note>
|
---|
48 |
|
---|
49 | <sect3 id="systemd-networkd-static">
|
---|
50 | <title>Static IP Configuration</title>
|
---|
51 |
|
---|
52 | <para>The command below creates a basic configuration file for
|
---|
53 | Static IP setup:</para>
|
---|
54 |
|
---|
55 | <screen role="nodump"><userinput>cat > /etc/systemd/network/10-static-eth0.network << "EOF"
|
---|
56 | <literal>[Match]
|
---|
57 | Name=eth0
|
---|
58 |
|
---|
59 | [Network]
|
---|
60 | Address=192.168.0.2/24
|
---|
61 | Gateway=192.168.0.1
|
---|
62 | DNS=192.168.0.1</literal>
|
---|
63 | EOF</userinput></screen>
|
---|
64 |
|
---|
65 | <para>More than one DNS entry can be specified in the configuration file.</para>
|
---|
66 |
|
---|
67 | </sect3>
|
---|
68 |
|
---|
69 | <sect3 id="systemd-networkd-dhcp">
|
---|
70 | <title>DHCP Configuration</title>
|
---|
71 |
|
---|
72 | <para>The command below creates a basic configuration file for
|
---|
73 | DHCP setup:</para>
|
---|
74 |
|
---|
75 | <screen role="nodump"><userinput>cat > /etc/systemd/network/10-dhcp-eth0.network << "EOF"
|
---|
76 | <literal>[Match]
|
---|
77 | Name=eth0
|
---|
78 |
|
---|
79 | [Network]
|
---|
80 | DHCP=yes</literal>
|
---|
81 | EOF</userinput></screen>
|
---|
82 |
|
---|
83 | <para>Note that <command>systemd-networkd</command> can only handle
|
---|
84 | DHCPv4. DHCPv6 support is a work in progress.</para>
|
---|
85 |
|
---|
86 | </sect3>
|
---|
87 |
|
---|
88 | </sect2>
|
---|
89 |
|
---|
90 | <sect2 id="resolv.conf">
|
---|
91 | <title>Creating the /etc/resolv.conf File</title>
|
---|
92 |
|
---|
93 | <indexterm zone="resolv.conf">
|
---|
94 | <primary sortas="e-/etc/resolv.conf">/etc/resolv.conf</primary>
|
---|
95 | </indexterm>
|
---|
96 |
|
---|
97 | <para>If the system is going to be connected to the Internet, it will
|
---|
98 | need some means of Domain Name Service (DNS) name resolution to
|
---|
99 | resolve Internet domain names to IP addresses, and vice versa. This is
|
---|
100 | best achieved by placing the IP address of the DNS server, available
|
---|
101 | from the ISP or network administrator, into
|
---|
102 | <filename>/etc/resolv.conf</filename>.</para>
|
---|
103 |
|
---|
104 | <para>When using <command>systemd-networkd</command> for network
|
---|
105 | configuration, another daemon, <command>systemd-resolved</command>,
|
---|
106 | is responsible for creating the <filename>/etc/resolv.conf</filename>
|
---|
107 | file. It is, however, placed in a non-standard location which is
|
---|
108 | writable since early boot, so it is necessary to create a symlink
|
---|
109 | to it by running the following command:</para>
|
---|
110 |
|
---|
111 | <screen><userinput>ln -sfv /run/systemd/resolve/resolv.conf /etc/resolv.conf</userinput></screen>
|
---|
112 |
|
---|
113 | <para>If static <filename>/etc/resolv.conf</filename> is desired, create
|
---|
114 | it by running the following command:</para>
|
---|
115 |
|
---|
116 | <screen><userinput>cat > /etc/resolv.conf << "EOF"
|
---|
117 | <literal># Begin /etc/resolv.conf
|
---|
118 |
|
---|
119 | domain <replaceable><Your Domain Name></replaceable>
|
---|
120 | nameserver <replaceable><IP address of your primary nameserver></replaceable>
|
---|
121 | nameserver <replaceable><IP address of your secondary nameserver></replaceable>
|
---|
122 |
|
---|
123 | # End /etc/resolv.conf</literal>
|
---|
124 | EOF</userinput></screen>
|
---|
125 |
|
---|
126 | <para>The <varname>domain</varname> statement can be omitted
|
---|
127 | or replaced with a <varname>search</varname> statement. See the man page for
|
---|
128 | resolv.conf for more details.</para>
|
---|
129 |
|
---|
130 | <para>Replace <replaceable><IP address of the nameserver></replaceable>
|
---|
131 | with the IP address of the DNS most appropriate for the setup. There will
|
---|
132 | often be more than one entry (requirements demand secondary servers for
|
---|
133 | fallback capability). If you only need or want one DNS server, remove the
|
---|
134 | second <emphasis>nameserver</emphasis> line from the file. The IP address
|
---|
135 | may also be a router on the local network.</para>
|
---|
136 |
|
---|
137 | <note><para>The Google Public IPv4 DNS addresses are 8.8.8.8 and 8.8.4.4.</para></note>
|
---|
138 |
|
---|
139 | </sect2>
|
---|
140 |
|
---|
141 | <sect2 id="ch-scripts-hostname">
|
---|
142 | <title>Configuring the system hostname</title>
|
---|
143 |
|
---|
144 | <indexterm zone="ch-scripts-hostname">
|
---|
145 | <primary sortas="d-hostname">hostname</primary>
|
---|
146 | <secondary>configuring</secondary>
|
---|
147 | </indexterm>
|
---|
148 |
|
---|
149 | <para>During the boot process, the file <filename>/etc/hostname</filename>
|
---|
150 | is used for establishing the system's hostname.</para>
|
---|
151 |
|
---|
152 | <para>Create the <filename>/etc/hostname</filename> file and enter a
|
---|
153 | hostname by running:</para>
|
---|
154 |
|
---|
155 | <screen><userinput>echo "<replaceable><lfs></replaceable>" > /etc/hostname</userinput></screen>
|
---|
156 |
|
---|
157 | <para><replaceable><lfs></replaceable> needs to be replaced with the
|
---|
158 | name given to the computer. Do not enter the Fully Qualified Domain Name
|
---|
159 | (FQDN) here. That information is put in the
|
---|
160 | <filename>/etc/hosts</filename> file.</para>
|
---|
161 |
|
---|
162 | </sect2>
|
---|
163 |
|
---|
164 | <sect2 id="ch-scripts-hosts">
|
---|
165 | <title>Customizing the /etc/hosts File</title>
|
---|
166 |
|
---|
167 | <indexterm zone="ch-scripts-hosts">
|
---|
168 | <primary sortas="e-/etc/hosts">/etc/hosts</primary>
|
---|
169 | </indexterm>
|
---|
170 |
|
---|
171 | <indexterm zone="ch-scripts-hosts">
|
---|
172 | <primary sortas="d-localnet">localnet</primary>
|
---|
173 | <secondary>/etc/hosts</secondary>
|
---|
174 | </indexterm>
|
---|
175 |
|
---|
176 | <indexterm zone="ch-scripts-hosts">
|
---|
177 | <primary sortas="d-network">network</primary>
|
---|
178 | <secondary>/etc/hosts</secondary>
|
---|
179 | </indexterm>
|
---|
180 |
|
---|
181 | <para>Decide on the IP address, fully-qualified domain name (FQDN), and
|
---|
182 | possible aliases for use in the <filename>/etc/hosts</filename> file. The
|
---|
183 | syntax is:</para>
|
---|
184 |
|
---|
185 | <screen><literal>IP_address myhost.example.org aliases</literal></screen>
|
---|
186 |
|
---|
187 | <para>Unless the computer is to be visible to the Internet (i.e., there is
|
---|
188 | a registered domain and a valid block of assigned IP addresses—most
|
---|
189 | users do not have this), make sure that the IP address is in the private
|
---|
190 | network IP address range. Valid ranges are:</para>
|
---|
191 |
|
---|
192 | <screen><literal>Private Network Address Range Normal Prefix
|
---|
193 | 10.0.0.1 - 10.255.255.254 8
|
---|
194 | 172.x.0.1 - 172.x.255.254 16
|
---|
195 | 192.168.y.1 - 192.168.y.254 24</literal></screen>
|
---|
196 |
|
---|
197 | <para>x can be any number in the range 16-31. y can be any number in the
|
---|
198 | range 0-255.</para>
|
---|
199 |
|
---|
200 | <para>A valid private IP address could be 192.168.1.1. A valid FQDN for
|
---|
201 | this IP could be lfs.example.org.</para>
|
---|
202 |
|
---|
203 | <para>Even if not using a network card, a valid FQDN is still required.
|
---|
204 | This is necessary for certain programs to operate correctly.</para>
|
---|
205 |
|
---|
206 | <para>Create the <filename>/etc/hosts</filename> file by running:</para>
|
---|
207 |
|
---|
208 | <screen><userinput>cat > /etc/hosts << "EOF"
|
---|
209 | <literal># Begin /etc/hosts (network card version)
|
---|
210 |
|
---|
211 | 127.0.0.1 localhost
|
---|
212 | ::1 localhost
|
---|
213 | <replaceable><192.168.0.2></replaceable> <replaceable><HOSTNAME.example.org></replaceable> <replaceable>[alias1] [alias2] ...</replaceable>
|
---|
214 |
|
---|
215 | # End /etc/hosts (network card version)</literal>
|
---|
216 | EOF</userinput></screen>
|
---|
217 |
|
---|
218 | <para>The <replaceable><192.168.0.2></replaceable> and
|
---|
219 | <replaceable><HOSTNAME.example.org></replaceable> values need to be
|
---|
220 | changed for specific uses or requirements (if assigned an IP address by a
|
---|
221 | network/system administrator and the machine will be connected to an
|
---|
222 | existing network). The optional alias name(s) can be omitted.</para>
|
---|
223 |
|
---|
224 | <para>If a network card is not going to be configured, create the
|
---|
225 | <filename>/etc/hosts</filename> file by running:</para>
|
---|
226 |
|
---|
227 | <screen role="nodump"><userinput>cat > /etc/hosts << "EOF"
|
---|
228 | <literal># Begin /etc/hosts (no network card version)
|
---|
229 |
|
---|
230 | 127.0.0.1 <replaceable><HOSTNAME.example.org></replaceable> <replaceable><HOSTNAME></replaceable> localhost
|
---|
231 | ::1 localhost
|
---|
232 |
|
---|
233 | # End /etc/hosts (no network card version)</literal>
|
---|
234 | EOF</userinput></screen>
|
---|
235 |
|
---|
236 | <para>The ::1 entry is the IPv6 counterpart of 127.0.0.1 and represents the IPv6 loopback interface.</para>
|
---|
237 |
|
---|
238 | </sect2>
|
---|
239 |
|
---|
240 | </sect1>
|
---|