Added how to turn on routing/set up routes to the faq

www/faq.html

@@ -40,10 +40,12 @@
      <li> <a href="#SWS-2">How do I select which OS to run on each node?</a>
      <li> <a href="#SWS-3">Can I load my own software (RPMs) on my nodes?</a>
      <li> <a href="#SWS-4">Can I schedule programs to run
-                           automatically when a node boots</a>
-     <li> <a href="#SWS-5">How does my software determine when other
+                           automatically when a node boots?</a>
+     <li> <a href="#SWS-5">How can I turn on routing or set up routes
+			   automatically in my nodes?</a>
+     <li> <a href="#SWS-6">How does my software determine when other
                            nodes in my experiment are ready?</a>
-     <li> <a href="#SWS-6">Can I run my own Operating System?</a>
+     <li> <a href="#SWS-7">Can I run my own Operating System?</a>
      </ul>
 
 <li> <a href="#SEC">Security Issues</a>
@@ -347,8 +349,66 @@
     <a href = "tutorial/tutorial.php3">Emulab Tutorial</a> for an
     example.
     </p>    
-    
+
 <li><a NAME="SWS-5"></a>
+    <h3>How can I turn on routing or set up routes automatically 
+    in my nodes?</h3>
+    <p>
+    You can use command mentioned above (<tt>tb-set-node-startup</tt>)
+    in your NS file to specify a simple script in your home directory
+    that will do this. For instance, if I had a node called router,
+    and wanted to turn on routing in it, I would add these two lines
+    to my NS file:
+<pre>
+tb-set-node-os $router FBSD40-STD
+tb-set-node-startup $router /users/myname/router-startup
+</pre>
+    That would cause router to boot FreeBSD, and call my
+    router-startup script, which should look like this:
+<pre>
+#!/bin/sh
+/usr/site/bin/su1 sysctl -w net.inet.ip.forwarding=1
+/usr/site/bin/su1 sysctl -w net.inet.ip.fastforwarding=1
+exit 0
+</pre>
+    That will make sure that routing gets turned on when my router
+    node boots. Now say I have a client on one side of the router,
+    and a server on the other side, and I want to establish a route
+    from the client to the server through the router, and vice
+    versa. I would add these lines to my NS file:
+<pre>
+tb-set-node-startup $client /users/myname/clientroutecmd
+tb-set-node-startup $server /users/myname/serverroutecmd
+</pre>
+    This will have the client and the server each call a small script
+    to set up routes. To add a route (on client) to interface 0 of the
+    server through router, I would run a script called clientroutecmd
+    that looks like this (for a node running FreeBSD):
+<pre>
+#!/bin/sh
+sudo route add server-0 router
+exit 0
+</pre>
+    Similarly, to add a route (on server) to interface 0 of the client
+    through router, I would use this serverroutecmd script:
+<pre>
+#!/bin/sh
+sudo route add client-0 router
+exit 0
+</pre>
+    That should do it. We now will have a router node that really
+    routes and forwards packets, and a client and a server that know
+    how to talk to each other through a gateway router.
+    </p>
+    <p>
+    Please see the
+    <a href="docwrapper.php3?docname=tutorial/nscommands.html">Extensions</a>
+    page for a summary of all Emulab NS extensions, and the
+    <a href = "tutorial/tutorial.php3">Emulab Tutorial</a> for an
+    example.
+    </p>
+    
+<li><a NAME="SWS-6"></a>
     <h3>How does my software determine when other nodes in my
     experiment are ready?</h3>
     <p>
@@ -370,7 +430,7 @@
     Daemon</a> documentation.
     </p>
     
-<li><a NAME="SWS-6"></a>
+<li><a NAME="SWS-7"></a>
     <h3>Can I run my own Operating System?</h3>
     <p>
     Yes! You can run your own OS on any of the PCs (the Sharks do not