Intro: improved explenation why iptables are needed

diff --git a/1intro.tex b/1intro.tex
index 1faf5c8..99ade5d 100644 (file)
--- a/1intro.tex
+++ b/1intro.tex
@@ -18,9 +18,10 @@ Java\footnote{\url{http://www.java.com}} TCP driven echo server that executed
 on a virtualized Ubuntu system\footnote{\url{http://www.ubuntu.com}} running on
 the Linux kernel\footnote{\url{http://www.kernel.org}} version $3.13$. To test
 the error behaviour custom iptables output policies have to be
-set Listing~\ref{listing:iptables}. This is needen because the OS by default 
+set Listing~\ref{listing:iptables}. This is needed because the kernel by default 
 closes all connections from unknown sources and the manually created TCP 
-connections used in testing the implementation are unknown to the OS.
+packets used in testing the implementation are from a source unknown to the 
+kernel.
 
 \begin{lstlisting}[label={listing:iptables},caption={settings iptables}]
 Chain OUTPUT (policy ACCEPT)