[3f8be484] | 1 | <?xml version="1.0" encoding="ISO-8859-1"?> |
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| 2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" |
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| 3 | "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [ |
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| 4 | <!ENTITY % general-entities SYSTEM "../../general.ent"> |
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| 5 | %general-entities; |
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| 6 | ]> |
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| 7 | |
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| 8 | <sect1 id="ch-scripts-network"> |
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| 9 | <?dbhtml filename="network.html"?> |
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| 10 | |
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| 11 | <title>Configuring the network Script</title> |
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| 12 | |
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| 13 | <indexterm zone="ch-scripts-network"> |
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| 14 | <primary sortas="d-network">network</primary> |
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| 15 | <secondary>configuring</secondary></indexterm> |
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| 16 | |
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| 17 | <para>This section only applies if a network card is to be |
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| 18 | configured.</para> |
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| 19 | |
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| 20 | <para>If a network card will not be used, there is likely no need to |
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| 21 | create any configuration files relating to network cards. If that is |
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| 22 | the case, remove the <filename class="symlink">network</filename> |
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| 23 | symlinks from all run-level directories (<filename |
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| 24 | class="directory">/etc/rc.d/rc*.d</filename>).</para> |
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| 25 | |
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| 26 | <sect2> |
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| 27 | <title>Creating Network Interface Configuration Files</title> |
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| 28 | |
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| 29 | <para>Which interfaces are brought up and down by the network script |
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| 30 | depends on the files and directories in the <filename |
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| 31 | class="directory">/etc/sysconfig/network-devices</filename> hierarchy. |
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| 32 | This directory should contain a sub-directory for each interface to be |
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| 33 | configured, such as <filename>ifconfig.xyz</filename>, where |
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| 34 | <quote>xyz</quote> is a network interface name. Inside this directory |
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| 35 | would be files defining the attributes to this interface, such as its |
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| 36 | IP address(es), subnet masks, and so forth.</para> |
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| 37 | |
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| 38 | <para>The following command creates a sample <filename>ipv4</filename> |
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| 39 | file for the <filename class="devicefile">eth0</filename> device:</para> |
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| 40 | |
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| 41 | <screen><userinput>cd /etc/sysconfig/network-devices && |
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[661d1a4] | 42 | mkdir -v ifconfig.eth0 && |
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[3f8be484] | 43 | cat > ifconfig.eth0/ipv4 << "EOF" |
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| 44 | <literal>ONBOOT=yes |
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| 45 | SERVICE=ipv4-static |
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| 46 | IP=192.168.1.1 |
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| 47 | GATEWAY=192.168.1.2 |
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| 48 | PREFIX=24 |
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| 49 | BROADCAST=192.168.1.255</literal> |
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| 50 | EOF</userinput></screen> |
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| 51 | |
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| 52 | <para>The values of these variables must be changed in every file to |
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| 53 | match the proper setup. If the <envar>ONBOOT</envar> variable is |
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| 54 | set to <quote>yes</quote> the network script will bring up the |
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| 55 | Network Interface Card (NIC) during booting of the system. If set |
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| 56 | to anything but <quote>yes</quote> the NIC will be ignored by the |
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| 57 | network script and not brought up.</para> |
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| 58 | |
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| 59 | <para>The <envar>SERVICE</envar> variable defines the method used for |
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[fb40919] | 60 | obtaining the IP address. The CLFS-Bootscripts package has a modular IP |
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[3f8be484] | 61 | assignment format, and creating additional files in the <filename |
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| 62 | class="directory">/etc/sysconfig/network-devices/services</filename> |
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| 63 | directory allows other IP assignment methods. This is commonly used |
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| 64 | for Dynamic Host Configuration Protocol (DHCP), which is addressed in |
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| 65 | the BLFS book.</para> |
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| 66 | |
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| 67 | <para>The <envar>GATEWAY</envar> variable should contain the default |
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| 68 | gateway IP address, if one is present. If not, then comment out the |
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| 69 | variable entirely.</para> |
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| 70 | |
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| 71 | <para>The <envar>PREFIX</envar> variable needs to contain the number |
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| 72 | of bits used in the subnet. Each octet in an IP address is 8 bits. |
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| 73 | If the subnet's netmask is 255.255.255.0, then it is using the first |
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| 74 | three octets (24 bits) to specify the network number. If the netmask |
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| 75 | is 255.255.255.240, it would be using the first 28 bits. Prefixes |
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| 76 | longer than 24 bits are commonly used by DSL and cable-based Internet |
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| 77 | Service Providers (ISPs). In this example (PREFIX=24), the netmask is |
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| 78 | 255.255.255.0. Adjust the <envar>PREFIX</envar> variable according to |
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| 79 | your specific subnet.</para> |
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| 80 | |
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| 81 | </sect2> |
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| 82 | |
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| 83 | <sect2 id="resolv.conf"> |
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| 84 | <title>Creating the /etc/resolv.conf File</title> |
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| 85 | |
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| 86 | <indexterm zone="resolv.conf"> |
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| 87 | <primary sortas="e-/etc/resolv.conf">/etc/resolv.conf</primary> |
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| 88 | </indexterm> |
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| 89 | |
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| 90 | <para>If the system is going to be connected to the Internet, it will |
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| 91 | need some means of Domain Name Service (DNS) name resolution to resolve |
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| 92 | Internet domain names to IP addresses, and vice versa. This is best |
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| 93 | achieved by placing the IP address of the DNS server, available from |
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| 94 | the ISP or network administrator, into <filename>/etc/resolv.conf</filename>. |
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| 95 | Create the file by running the following:</para> |
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| 96 | |
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| 97 | <screen><userinput>cat > /etc/resolv.conf << "EOF" |
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| 98 | <literal># Begin /etc/resolv.conf |
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| 99 | |
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| 100 | domain {<replaceable>[Your Domain Name]</replaceable>} |
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| 101 | nameserver <replaceable>[IP address of your primary nameserver]</replaceable> |
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| 102 | nameserver <replaceable>[IP address of your secondary nameserver]</replaceable> |
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| 103 | |
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| 104 | # End /etc/resolv.conf</literal> |
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| 105 | EOF</userinput></screen> |
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| 106 | |
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| 107 | <para>Replace <replaceable>[IP address of the nameserver]</replaceable> |
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| 108 | with the IP address of the DNS most appropriate for the setup. There will |
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| 109 | often be more than one entry (requirements demand secondary servers for |
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| 110 | fallback capability). If you only need or want one DNS server, remove the |
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| 111 | second <emphasis>nameserver</emphasis> line from the file. The IP address |
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| 112 | may also be a router on the local network.</para> |
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| 113 | |
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| 114 | </sect2> |
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| 115 | |
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| 116 | </sect1> |
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