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Diffstat (limited to 'chapter07/network.xml')
| -rw-r--r-- | chapter07/network.xml | 219 |
1 files changed, 123 insertions, 96 deletions
diff --git a/chapter07/network.xml b/chapter07/network.xml index 4134bb40c..97ecf894e 100644 --- a/chapter07/network.xml +++ b/chapter07/network.xml @@ -24,106 +24,11 @@ class="directory">/etc/rc.d/rc*.d</filename>) after the bootscripts are installed in <xref linkend="ch-scripts-bootscripts"/>.</para> - <sect2 id='stable-net-names'> - <title>Creating stable names for network interfaces</title> - - <para>If there is only one network interface in the system to be - configured, this section is optional, although it will never be wrong to do - it. In many cases (e.g. a laptop with a wireless and a wired interface), - accomplishing the configuration in this section is necessary.</para> - - <para>With Udev and modular network drivers, the network interface numbering - is not persistent across reboots by default, because the drivers are loaded - in parallel and, thus, in random order. For example, on a computer having - two network cards made by Intel and Realtek, the network card manufactured - by Intel may become <filename class="devicefile">eth0</filename> and the - Realtek card becomes <filename class="devicefile">eth1</filename>. In some - cases, after a reboot the cards get renumbered the other way around. To - avoid this, Udev comes with a script and some rules to assign stable names - to network cards based on their MAC address.</para> - - <para>If using the traditional network interface names such as eth0 is desired, - generate a custom Udev rule:</para> - -<screen><userinput>bash /lib/udev/init-net-rules.sh</userinput></screen> - - <para> Now, inspect the - <filename>/etc/udev/rules.d/70-persistent-net.rules</filename> file, to - find out which name was assigned to which network device:</para> - -<screen role="nodump"><userinput>cat /etc/udev/rules.d/70-persistent-net.rules</userinput></screen> - - <note><para>In some cases such as when MAC addresess have been assigned to - a network card manually or in a virtual environment such as Xen, - the network rules file may not have been generated because addresses - are not consistently assigned. In these cases, just continue to - the next section.</para></note> - - <para>The file begins with a comment block followed by two lines for each - NIC. The first line for each NIC is a commented description showing its - hardware IDs (e.g. its PCI vendor and device IDs, if it's a PCI card), - along with its driver in parentheses, if the driver can be found. Neither - the hardware ID nor the driver is used to determine which name to give an - interface; this information is only for reference. The second line is the - Udev rule that matches this NIC and actually assigns it a name.</para> - - <para>All Udev rules are made up of several keys, separated by commas and - optional whitespace. This rule's keys and an explanation of each of them - are as follows:</para> - - <itemizedlist> - <listitem> - <para><literal>SUBSYSTEM=="net"</literal> - This tells Udev to ignore - devices that are not network cards.</para> - </listitem> - <listitem> - <para><literal>ACTION=="add"</literal> - This tells Udev to ignore this - rule for a uevent that isn't an add ("remove" and "change" uevents also - happen, but don't need to rename network interfaces).</para> - </listitem> - <listitem> - <para><literal>DRIVERS=="?*"</literal> - This exists so that Udev will - ignore VLAN or bridge sub-interfaces (because these sub-interfaces do - not have drivers). These sub-interfaces are skipped because the name - that would be assigned would collide with their parent devices.</para> - </listitem> - <listitem> - <para><literal>ATTR{address}</literal> - The value of this key is the - NIC's MAC address.</para> - </listitem> - <listitem> - <para><literal>ATTR{type}=="1"</literal> - This ensures the rule only - matches the primary interface in the case of certain wireless drivers, - which create multiple virtual interfaces. The secondary interfaces are - skipped for the same reason that VLAN and bridge sub-interfaces are - skipped: there would be a name collision otherwise.</para> - </listitem> - <listitem> - <para><literal>KERNEL=="eth*"</literal> - This key was added to the - Udev rule generator to handle machines that have multiple network - interfaces, all with the same MAC address (the PS3 is one such - machine). If the independent interfaces have different basenames, - this key will allow Udev to tell them apart. This is generally not - necessary for most Linux From Scratch users, but does not hurt.</para> - </listitem> - <listitem> - <para><literal>NAME</literal> - The value of this key is the name that - Udev will assign to this interface.</para> - </listitem> - </itemizedlist> - - <para>The value of <literal>NAME</literal> is the important part. Make sure - you know which name has been assigned to each of your network cards before - proceeding, and be sure to use that <literal>NAME</literal> value when - creating your configuration files below.</para> - - </sect2> - <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 + usually 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 @@ -216,12 +121,38 @@ EOF</userinput></screen> <para>Replace eth0 with the correct network interface card name as described on the beginning of this page.</para> + <note><para>These procedures require the configuartion files as specified + in the previous section.</para></note> + <note><para>The network card can also be started or stopped with the traditional <command>ifup <device></command> or <command>ifdown <device></command> commands.</para></note> </sect2> + <sect2 id="systemd2-net-enable"> + <title>Configuring the Network Interface Card for systemd-networkd</title> + + <para>An alternative way to configure a NIC when booting with with + systemd is to create a configuration file recognized by the + systemd-networkd daemon. To configure the device create a file similar + to this:</para> + +<screen role="nodump"><userinput>cat > /etc/systemd/network/10-static-eth0.network << "EOF" +[Match] +Name=eth0 + +[Network] +Address=192.168.0.2/24 +Gateway=192.168.0.1 +EOF</userinput></screen> + + <para>You can use multiple .network files if desired. You can also specify + DHCP=yes instead of the Address and Gateway settings. See the man page for + systemd.network for more details,</para> + + </sect2> + <sect2 id="resolv.conf"> <title>Creating the /etc/resolv.conf File</title> @@ -262,4 +193,100 @@ EOF</userinput></screen> </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, both Systemd and System V use the same file + for establishing the system's hostname. This needs to be configured by + creating <filename>/etc/hostname</filename>.</para> + + <para>Create the <filename>/etc/hostname</filename> file and enter a + hostname by running:</para> + +<screen><userinput>echo "<replaceable><lfs></replaceable>" > /etc/hostname</userinput></screen> + + <para><replaceable><lfs></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—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 > /etc/hosts << "EOF" +<literal># Begin /etc/hosts (network card version) + +127.0.0.1 localhost +<replaceable><192.168.1.1></replaceable> <replaceable><HOSTNAME.example.org></replaceable> <replaceable>[alias1] [alias2 ...]</replaceable> + +# End /etc/hosts (network card version)</literal> +EOF</userinput></screen> + + <para>The <replaceable><192.168.1.1></replaceable> and + <replaceable><HOSTNAME.example.org></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 > /etc/hosts << "EOF" +<literal># Begin /etc/hosts (no network card version) + +127.0.0.1 <replaceable><HOSTNAME.example.org></replaceable> <replaceable><HOSTNAME></replaceable> localhost + +# End /etc/hosts (no network card version)</literal> +EOF</userinput></screen> + + </sect2> + </sect1> |