diff --git a/chapter/layer3.tex b/chapter/layer3.tex
index 1ff3a68..b8da8ee 100644
--- a/chapter/layer3.tex
+++ b/chapter/layer3.tex
@@ -184,6 +184,10 @@ Known adoptions of EIGRP includes:
     \item Quagga has known works for trying to implement \gls{eigrp}. Still not officially implemented, thou.
 \end{itemize}
 
+\subsection{Filtering}
+
+\gls{eigrp} routing updates can of course be filtered in- and outgoing direction on Cisco boxes by using prefix-lists and applying the prefix lists under the \texttt{router eigrp x} process.
+
 \newpage
 
 \section{RIP}