Answer the often asked 'bpf' questions.

Requested By:	some people on -net

FAQ/network.sgml

@@ -1,4 +1,4 @@
-<!-- $Id: network.sgml,v 1.18 1998-11-22 14:03:32 jkh Exp $ -->
+<!-- $Id: network.sgml,v 1.19 1999-01-26 21:25:11 billf Exp $ -->
 <!-- The FreeBSD Documentation Project -->
 
   <sect>
@@ -1154,6 +1154,29 @@ ftp stream tcp nowait nobody /usr/local/bin/socket socket ftp.foo.com ftp
        <url url="http://www.etinc.com" name="Emerging Technologies"> is
        a commercial product. 
 
+     <sect1>
+       <heading>Why do I get ``/dev/bpf0: device not configured"?</heading>
+
+       <p>The Berkeley Packet Filter <htmlurl
+       url="http://www.FreeBSD.org/cgi/man.cgi?bpf" name="(bpf)"> driver
+       needs to be enabled before running programs that utilize it. 
+       Add this to your kernel config file and build a new kernel:
+
+       <verb>
+	 pseudo-device bpfilter		# Berkeley Packet Filter
+       </verb>
+
+       <p>Secondly, after rebooting you will have to create the device
+       node. This can be accomplished by a change to the <tt>/dev</tt>
+       directory, followed by the execution of:
+
+       <tscreen><verb>
+       # sh MAKEDEV bpf0
+       </verb></tscreen>
+
+       <p>Please see the <htmlurl url="../handbook/kernelconfig:nodes.html"
+       name "handbook's entry on device nodes"> for more information
+       on creating devices.
 
   </sect>