Changeset de17e85 in clfs-sysroot for BOOK/bootscripts/common
- Timestamp:
- Nov 7, 2006, 12:23:07 PM (18 years ago)
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- master
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- 71d6e4a
- Parents:
- 5fc4a87
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BOOK/bootscripts/common/network.xml
r5fc4a87 rde17e85 23 23 symlinks from all run-level directories (<filename 24 24 class="directory">/etc/rc.d/rc*.d</filename>).</para> 25 26 <sect2>27 <title>Creating stable names for network interfaces</title>28 29 <para>Instructions in this section are optional if you have only one30 network card.</para>31 32 <para>With Udev and modular network drivers, the network interface numbering33 is not persistent across reboots by default, because the drivers are loaded34 in parallel and, thus, in random order. For example, on a computer having35 two network cards made by Intel and Realtek, the network card manufactured36 by Intel may become <filename class="devicefile">eth0</filename> and the37 Realtek card becomes <filename class="devicefile">eth1</filename>. In some38 cases, after a reboot the cards get renumbered the other way around. To39 avoid this, create Udev rules that assign stable names to network cards40 based on their MAC addresses or bus positions.</para>41 42 <para>If you are going to use MAC addresses to identify your network43 cards, find the addresses with the following command:</para>44 45 <screen role="nodump"><userinput>grep -H . /sys/class/net/*/address</userinput></screen>46 47 <para>For each network card (but not for the loopback interface),48 invent a descriptive name, such as <quote>realtek</quote>, and create49 Udev rules similar to the following:</para>50 51 <screen role="nodump"><userinput>cat > /etc/udev/rules.d/26-network.rules << EOF52 <literal>ACTION=="add", SUBSYSTEM=="net", SYSFS{address}=="<replaceable>00:e0:4c:12:34:56</replaceable>", \53 NAME="<replaceable>realtek</replaceable>"54 ACTION=="add", SUBSYSTEM=="net", SYSFS{address}=="<replaceable>00:a0:c9:78:9a:bc</replaceable>", \55 NAME="<replaceable>intel</replaceable>"</literal>56 EOF</userinput></screen>57 58 <!-- Yes, I know that VLANs are beyond BLFS. This is not the reason to get them59 incorrect by default when every distro does this right. -->60 61 <note>62 <para>Although the examples in this book work properly, be aware63 that Udev does not recognize the backslash for line continuation.64 If modifying Udev rules with an editor, be sure to leave each rule65 on one physical line.</para>66 </note>67 68 <para>If you are going to use the bus position as a key, create69 Udev rules similar to the following:</para>70 71 <screen role="nodump"><userinput>cat > /etc/udev/rules.d/26-network.rules << EOF72 <literal>ACTION=="add", SUBSYSTEM=="net", BUS=="<replaceable>pci</replaceable>", ID=="<replaceable>0000:00:0c.0</replaceable>", \73 NAME="<replaceable>realtek</replaceable>"74 ACTION=="add", SUBSYSTEM=="net", BUS=="<replaceable>pci</replaceable>", ID=="<replaceable>0000:00:0d.0</replaceable>", \75 NAME="<replaceable>intel</replaceable>"</literal>76 EOF</userinput></screen>77 78 <para>These rules will always rename the network cards to79 <quote>realtek</quote> and <quote>intel</quote>, independently80 of the original numbering provided by the kernel (i.e.: the original81 <quote>eth0</quote> and <quote>eth1</quote> interfaces will no longer82 exist, unless you put such <quote>descriptive</quote> names in the NAME83 key). Use the descriptive names from the Udev rules instead84 of <quote>eth0</quote> in the network interface configuration files85 below.</para>86 87 <para>Note that the rules above don't work for every setup. For example,88 MAC-based rules break when bridges or VLANs are used, because bridges and89 VLANs have the same MAC address as the network card. One wants to rename90 only the network card interface, not the bridge or VLAN interface, but the91 example rule matches both. If you use such virtual interfaces, you have two92 potential solutions. One is to add the DRIVER=="?*" key after93 SUBSYSTEM=="net" in MAC-based rules which will stop matching the virtual94 interfaces. This is known to fail with some older Ethernet cards because95 they don't have the DRIVER variable in the uevent and thus the rule does96 not match with such cards. Another solution is to switch to rules that use97 the bus position as a key.</para>98 99 <para>The second known non-working case is with wireless cards using the100 MadWifi or HostAP drivers, because they create at least two interfaces with101 the same MAC address and bus position. For example, the Madwifi driver102 creates both an athX and a wifiX interface where X is a digit. To103 differentiate these interfaces, add an appropriate KERNEL parameter such as104 KERNEL=="ath*" after SUBSYSTEM=="net".</para>105 106 <para>There may be other cases where the rules above don't work. Currently,107 bugs on this topic are still being reported to Linux distributions, and no108 solution that covers every case is available.</para>109 110 </sect2>111 25 112 26 <sect2>
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