On Mon, Sep 04, 2006 at 10:36:27PM +0200, Hubert Feyrer wrote:
> On Mon, 4 Sep 2006, Pavel Cahyna wrote:
> >This is in fact the same case as with the above, just with a pseudo-device
> >instead of a physical device.
> >
> >BTW your statement that "Using ktrace(1)  can help you find what's going
> >on inside a command, and to determine you what's being accessed that may
> >cause the error message." is misleading. There is no need to use ktrace in
> >the case mentioned. pfctl tells you what device node did it attempt to
> >use. (/dev/pf)
> 
> Want to send me a patch to update the text?
> I'm not 100% sure what you're suggesting to change...

--- index.xml.~1.11.~	Mon Sep  4 22:46:30 2006
+++ index.xml	Mon Sep  4 23:29:37 2006
@@ -662,7 +662,7 @@
             node in <code>/dev</code> (e.g. a SCSI disk), this means
             that the driver can't find the specific device unit you
             tried to access, e.g. accessing a SCSI disk that isn't
-            there.
+            there, or the driver is not compiled in the kernel.
           </para>
 
           <para>
@@ -676,18 +676,33 @@
             <code>/var/run/dmesg.boot</code> (a saved copy of the
             boot time autoconfiguration output).
           </para>
-        </listitem>
-        <listitem>
-          <para>
-	    Another case where this can happen is when a certain kernel
-	    subsystem, e.g. some firewall, is not compiled into the
-	    kernel or loaded as an LKM, and when data is directed at
-	    that subsystem, e.g. when &man.pfctl.8; or &man.ipf.8;
-	    are used to load firewall rules.  Using &man.ktrace.1;
-	    can help you find what's going on inside a command, and
-	    to determine you what's being accessed that may cause
-	    the error message.
-          </para>
+
+	  <para>
+	    Another case where this can happen is when a certain
+	    kernel subsystem which is implemented as a pseudo-device
+	    is not compiled into the kernel or loaded as an LKM and a
+	    configuration program wants to configure it using a device
+	    node in <code>/dev</code>. For example when a firewall is
+	    not compiled into the kernel or loaded as an LKM and the
+	    &man.pfctl.8; or &man.ipf.8; utility attempts to load
+	    firewall rules. If such utility does not print a helpful
+	    message indicating what device it tried to use,
+	    &man.ktrace.1; can help you find what's going on inside a
+	    command, and to determine you what's being accessed that
+	    may cause the error message.
+	  </para>
+
+	  <para>
+	    And it can happen in many other cases when a nonexistent
+	    device or device without a driver is accessed, like when a
+	    nonexistent network interface name is passed to
+	    &man.ifconfig.8; (in this case, if you are sure that you
+	    have the right driver, maybe the interface must be
+	    explicitely created by a command like <code>ifconfig vlan0
+	    create</code> &mdash; this is true for most of the network
+	    pseudo-devices like &man.sl.4;, &man.vlan.4; or
+	    &man.stf.4;).
+	  </para>
         </listitem>
       </itemizedlist>
     </sect3>