title: Iptables Postrouting with SNAT for a paritcular destination IP
body: <p>I want to define a rule in iptables for postrouting in ubuntu as below:</p>
  
  <pre><code>$IPTABLES -t nat -A POSTROUTING  -o $EXTIF -p tcp -d xxx.xx.xx.8 -j SNAT --to-source xxx.xx.xx.238
  </code></pre>
  
  <p>It means for destination with IP xxx.xx.xx.8 (a oublic IP) , I want its source IP to be xxx.xx.xx.238. </p>
  
  <p>The above rule is not working . 
  Any suggestions.
  Thank you.</p>