man: add an example to (re-)apply new settings to a network interface

[thirdparty/systemd.git] / man / systemd.link.xml

diff --git a/man/systemd.link.xml b/man/systemd.link.xml
index cc55b02b182f3e7801188ec9f9057de93beecc13..546a6a006b20e1ba333f454abc71e307a31a98fd 100644 (file)
--- a/man/systemd.link.xml
+++ b/man/systemd.link.xml
@@ -273,7 +273,7 @@
         <term><varname>Credential=</varname></term>
         <listitem>
           <para>Checks whether the specified credential was passed to the
-          <filename>systemd-networkd.service</filename> service. See <ulink
+          <filename>systemd-udevd.service</filename> service. See <ulink
           url="https://systemd.io/CREDENTIALS">System and Service Credentials</ulink> for details. When
           prefixed with an exclamation mark (<literal>!</literal>), the result is negated.  If an empty
           string is assigned, the previously assigned value is cleared.
@@ -1111,12 +1111,15 @@
     <example>
       <title>/usr/lib/systemd/network/99-default.link</title>
 
-      <para>The link file <filename>99-default.link</filename> that is
-      shipped with systemd defines the default naming policy for
-      links.</para>
+      <para>The link file <filename>99-default.link</filename> that is shipped with systemd defines the
+      default policies for the interface name, alternative names, and MAC address of links.</para>
 
-      <programlisting>[Link]
-NamePolicy=kernel database onboard slot path
+      <programlisting>[Match]
+OriginalName=*
+
+[Link]
+NamePolicy=keep kernel database onboard slot path
+AlternativeNamesPolicy=database onboard slot path
 MACAddressPolicy=persistent</programlisting>
     </example>
 
@@ -1134,7 +1137,24 @@ Name=dmz0</programlisting>
 
       <para><varname>NamePolicy=</varname> is not set, so <varname>Name=</varname> takes effect. We use the
       <literal>10-</literal> prefix to order this file early in the list. Note that it needs to be before
-      <literal>99-link</literal>, i.e. it needs a numerical prefix, to have any effect at all.</para>
+      <filename>99-default.link</filename>, i.e. it needs a numerical prefix, to have any effect at all.</para>
+    </example>
+
+    <example>
+      <title>(Re-)applying a .link file to an interface</title>
+
+      <para>After a new .link file has been created, or an exisiting .link file modified, the new settings
+      may be applied to the matching interface with the following commands:</para>
+
+      <programlisting>$ sudo udevadm control --reload
+$ sudo ip link set eth0 down
+$ sudo udevadm trigger --verbose --settle --action add /sys/class/net/eth0</programlisting>
+
+      <para>You may also need to stop the service that manages the network interface, e.g.
+      <filename>systemd-networkd.service</filename> or <filename>NetworkManager.service</filename> before
+      the above operation, and then restart the service after that. For more details about
+      <command>udevadm</command> command, see
+      <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
     </example>
 
     <example>