Add Why would we want this?

slides.tex

@@ -82,4 +82,16 @@ routing protocol}
     \end{figure}
 \end{frame}
 
+\begin{frame}{Why would we want this?}
+    \begin{itemize}
+        \item Supporting both v4 and v6 is cumbersome: twice the configuration
+        \item v6-only core, still serve v4 to clients
+        \item IPv6 has \alert{link-local} and \alert{automatic addresses}
+            (SLAAC)
+            \begin{itemize}
+                \item no need for DHCP or IP configuration \emph{at all}!
+            \end{itemize}
+    \end{itemize}
+\end{frame}
+
 \end{document}