Index: chapter07/network.xml
===================================================================
--- chapter07/network.xml	(revision 94f4fb86521f57d6fabe8caecccd9d0ce316a6c1)
+++ chapter07/network.xml	(revision abadfc30042582a8593c2ddbc726f13249a14ab5)
@@ -19,92 +19,70 @@
 
   <sect2>
-    <title>Creating Network Interface Configuration Files</title>
-
-    <para>Which interfaces are brought up and down by the network script
-    depends on the files in <filename
-    class="directory">/etc/sysconfig/</filename>. This directory should
-    contain a file for each interface to be configured, such as
-    <filename>ifconfig.xyz</filename>, where <quote>xyz</quote> is
-    required to be a Network Card Interface name (e.g. eth0).
-    Inside this file are attributes to this interface, such as its IP
-    address(es), subnet masks, and so forth.  It is necessary that
-    the stem of the filename be <emphasis>ifconfig</emphasis>.</para>
-
-    <note><para>Udev may assign random Network Card Interface names
-    for some network cards such as enp2s1. If you are not sure what
-    your Network Card Interface name is, you can always run
-    <command>ip l</command> after you have booted your system. Again,
-    it is important that <filename>ifconfig.xyz</filename> is named
-    after correct Network Card Interface name (e.g.
-    <filename>ifconfig.enp2s1</filename> or
-    <filename>ifconfig.eth0</filename>) or Systemd will fail to bring
-    up your network interface.</para></note>
-
-    <para>The following command creates a sample file for the
-    <emphasis>eth0</emphasis> device with a static IP address:</para>
-
-<screen><userinput>cd /etc/sysconfig/
-cat &gt; ifconfig.eth0 &lt;&lt; "EOF"
-<literal>IFACE=eth0
-SERVICE=ipv4-static
-IP=192.168.1.1
-GATEWAY=192.168.1.2
-PREFIX=24
-BROADCAST=192.168.1.255</literal>
-EOF</userinput></screen>
-
-    <para>The values of these variables must be changed in every file to match
-    the proper setup.</para>
-
-    <para>The <envar>IFACE</envar> variable defines the interface name,
-    for example, eth0. It is required for all network device configuration
-    files.</para>
-
-    <para>The <envar>SERVICE</envar> variable defines the method used for
-    obtaining the IP address. The LFS-Network-Scripts package has a modular
-    IP assignment format, and creating additional files in the <filename
-    class="directory">/lib/services/</filename> directory allows other IP
-    assignment methods. This is commonly used for Dynamic Host Configuration
-    Protocol (DHCP), which is addressed in the BLFS book.</para>
-
-    <para>The <envar>GATEWAY</envar> variable should contain the default
-    gateway IP address, if one is present. If not, then comment out the
-    variable entirely.</para>
-
-    <para>The <envar>PREFIX</envar> variable contains the number of
-    bits used in the subnet. Each octet in an IP address is 8 bits. If the
-    subnet's netmask is 255.255.255.0, then it is using the first three octets
-    (24 bits) to specify the network number. If the netmask is 255.255.255.240,
-    it would be using the first 28 bits.  Prefixes longer than 24 bits are
-    commonly used by DSL and cable-based Internet Service Providers (ISPs).
-    In this example (PREFIX=24), the netmask is 255.255.255.0. Adjust the
-    <envar>PREFIX</envar> variable according to your specific subnet.
-    If omitted, the PREFIX defaults to 24.</para>
-
-    <para>For more information see the <command>ifup</command> man page.</para>
-
-  </sect2>
-
-  <sect2>
-    <title>Configuring the Network Interface Card at boot</title>
-
-    <para>Enabling of the Network Interface Card configuration is
-    done per interface. To enable Network Interface Card
-    configuration at boot, run:</para>
-
-<screen><userinput>systemctl enable ifupdown@eth0</userinput></screen>
-
-    <para>To disable previously enabled Network Interface
-    Card configuration at boot, run:</para>
-
-<screen><userinput>systemctl disable ifupdown@eth0</userinput></screen>
-
-    <para>To manually start the Network Interface Card configuration,
-    run:</para>
-
-<screen><userinput>systemctl start ifupdown@eth0</userinput></screen>
-
-    <para>Replace eth0 with the correct Network Interface Card
-    name as described on the beginning of this page.</para>
+    <title>Network Interface Configuration Files</title>
+
+    <para>Starting with version 209, systemd ships a network configuration
+    daemon called <command>systemd-networkd</command> which can be used for
+    basic network configuration.</para>
+
+    <para>Configuration files for <command>systemd-networkd</command> can be
+    placed in <filename class="directory">/usr/lib/systemd/network</filename>
+    or <filename class="directory">/etc/systemd/network</filename>. Note that
+    files in <filename class="directory">/etc/systemd/network</filename> have
+    higher priority than the ones in
+    <filename class="directory">/usr/lib/systemd/network</filename>.</para>
+
+    <para>There are three types of configuration files:
+    <filename class="extension">.link</filename>,
+    <filename class="extension">.netdev</filename> and
+    <filename class="extension">.network</filename> files. For detailed
+    explanation about contents of the mentioned
+    configuration files, consult <command>systemd-link(5)</command>,
+    <command>systemd-netdev(5)</command> and
+    <command>systemd-network(5)</command> manual pages.</para>
+
+    <note><para>Udev may assign network card interface names based
+    on system physical characteristics such as enp2s1. If you are
+    not sure what your interface name is, you can always run
+    <command>ip link</command> after you have booted your system.
+    </para></note>
+
+    <sect3 id="systemd-networkd-static">
+      <title>Static IP Configuration</title>
+
+      <para>The command below creates a basic configuration file for
+      Static IP setup:</para>
+
+<screen role="nodump"><userinput>cat &gt; /etc/systemd/network/10-static-eth0.network &lt;&lt; "EOF"
+<literal>[Match]
+Name=eth0
+
+[Network]
+Address=192.168.0.2/24
+Gateway=192.168.0.1
+DNS=192.168.0.1</literal>
+EOF</userinput></screen>
+
+      <para>More than one DNS entry can be specified in the configuration file.</para>
+
+    </sect3>
+
+    <sect3 id="systemd-networkd-dhcp">
+      <title>DHCP Configuration</title>
+
+      <para>The command below creates a basic configuration file for
+      DHCP setup:</para>
+
+<screen role="nodump"><userinput>cat &gt; /etc/systemd/network/10-dhcp-eth0.network &lt;&lt; "EOF"
+<literal>[Match]
+Name=eth0
+
+[Network]
+DHCP=yes</literal>
+EOF</userinput></screen>
+
+      <para>Note that <command>systemd-networkd</command> can only handle
+      DHCPv4. DHCPv6 support is a work in progress.</para>
+
+    </sect3>
 
   </sect2>
@@ -122,6 +100,17 @@
     best achieved by placing the IP address of the DNS server, available
     from the ISP or network administrator, into
-    <filename>/etc/resolv.conf</filename>. Create the file by running the
-    following:</para>
+    <filename>/etc/resolv.conf</filename>.</para>
+
+    <para>When using <command>systemd-networkd</command> for network
+    configuration, another daemon, <command>systemd-resolved</command>,
+    is responsible for creating the <filename>/etc/resolv.conf</filename>
+    file. It is, however, placed in a non-standard location which is
+    writable since early boot, so it is necessary to create a symlink
+    to it by running the following command:</para>
+
+<screen><userinput>ln -sfv /run/systemd/resolve/resolv.conf /etc/resolv.conf</userinput></screen>
+
+    <para>If static <filename>/etc/resolv.conf</filename> is desired, create
+    it by running the following command:</para>
 
 <screen><userinput>cat &gt; /etc/resolv.conf &lt;&lt; "EOF"
@@ -150,3 +139,98 @@
   </sect2>
 
+  <sect2 id="ch-scripts-hostname">
+    <title>Configuring the system hostname</title>
+
+    <indexterm zone="ch-scripts-hostname">
+      <primary sortas="d-hostname">hostname</primary>
+      <secondary>configuring</secondary>
+    </indexterm>
+
+     <para>During the boot process, the file <filename>/etc/hostname</filename>
+     is used for establishing the system's hostname.</para>
+
+     <para>Create the <filename>/etc/hostname</filename> file and enter a
+     hostname by running:</para>
+
+<screen><userinput>echo "<replaceable>&lt;lfs&gt;</replaceable>" &gt; /etc/hostname</userinput></screen>
+
+     <para><replaceable>&lt;lfs&gt;</replaceable> needs to be replaced with the
+     name given to the computer. Do not enter the Fully Qualified Domain Name
+     (FQDN) here. That information is put in the
+     <filename>/etc/hosts</filename> file.</para>
+
+  </sect2>
+
+  <sect2 id="ch-scripts-hosts">
+     <title>Customizing the /etc/hosts File</title>
+
+     <indexterm zone="ch-scripts-hosts">
+       <primary sortas="e-/etc/hosts">/etc/hosts</primary>
+     </indexterm>
+   
+     <indexterm zone="ch-scripts-hosts">
+       <primary sortas="d-localnet">localnet</primary>
+       <secondary>/etc/hosts</secondary>
+     </indexterm>
+   
+     <indexterm zone="ch-scripts-hosts">
+       <primary sortas="d-network">network</primary>
+       <secondary>/etc/hosts</secondary>
+     </indexterm>
+   
+     <para>Decide on the IP address, fully-qualified domain name (FQDN), and
+     possible aliases for use in the <filename>/etc/hosts</filename> file. The
+     syntax is:</para>
+   
+<screen><literal>IP_address myhost.example.org aliases</literal></screen>
+
+     <para>Unless the computer is to be visible to the Internet (i.e., there is
+     a registered domain and a valid block of assigned IP addresses&mdash;most
+     users do not have this), make sure that the IP address is in the private
+     network IP address range. Valid ranges are:</para>
+
+<screen><literal>Private Network Address Range      Normal Prefix
+10.0.0.1 - 10.255.255.254           8
+172.x.0.1 - 172.x.255.254           16
+192.168.y.1 - 192.168.y.254         24</literal></screen>
+
+     <para>x can be any number in the range 16-31. y can be any number in the
+     range 0-255.</para>
+   
+     <para>A valid private IP address could be 192.168.1.1. A valid FQDN for
+     this IP could be lfs.example.org.</para>
+   
+     <para>Even if not using a network card, a valid FQDN is still required.
+     This is necessary for certain programs to operate correctly.</para>
+   
+     <para>Create the  <filename>/etc/hosts</filename> file by running:</para>
+
+<screen><userinput>cat &gt; /etc/hosts &lt;&lt; "EOF"
+<literal># Begin /etc/hosts (network card version)
+
+127.0.0.1 localhost
+<replaceable>&lt;192.168.0.2&gt;</replaceable> <replaceable>&lt;HOSTNAME.example.org&gt;</replaceable> <replaceable>[alias1] [alias2] ...</replaceable>
+
+# End /etc/hosts (network card version)</literal>
+EOF</userinput></screen>
+
+     <para>The <replaceable>&lt;192.168.0.2&gt;</replaceable> and
+     <replaceable>&lt;HOSTNAME.example.org&gt;</replaceable> values need to be
+     changed for specific uses or requirements (if assigned an IP address by a
+     network/system administrator and the machine will be connected to an
+     existing network). The optional alias name(s) can be omitted.</para>
+   
+     <para>If a network card is not going to be configured, create the
+     <filename>/etc/hosts</filename> file by running:</para>
+
+<screen role="nodump"><userinput>cat &gt; /etc/hosts &lt;&lt; "EOF"
+<literal># Begin /etc/hosts (no network card version)
+
+127.0.0.1 <replaceable>&lt;HOSTNAME.example.org&gt;</replaceable> <replaceable>&lt;HOSTNAME&gt;</replaceable> localhost
+
+# End /etc/hosts (no network card version)</literal>
+EOF</userinput></screen>
+
+   </sect2>
+
 </sect1>
