diff --git a/systemvm/debian/opt/cloud/bin/cs/CsAddress.py b/systemvm/debian/opt/cloud/bin/cs/CsAddress.py
old mode 100755
new mode 100644
index fe95808f7d32..72e196e67238
--- a/systemvm/debian/opt/cloud/bin/cs/CsAddress.py
+++ b/systemvm/debian/opt/cloud/bin/cs/CsAddress.py
@@ -889,7 +889,7 @@ def post_config_change(self, method):
                     ["nat", "", "-A POSTROUTING -j SNAT -o %s --to-source %s" % (self.dev, self.address['public_ip'])])
             elif cmdline.get_source_nat_ip() and not self.is_private_gateway():
                 self.fw.append(
-                    ["nat", "", "-A POSTROUTING -j SNAT -o %s --to-source %s" % (self.dev, cmdline.get_source_nat_ip())])
+                    ["nat", "", "-A POSTROUTING -m addrtype ! --src-type LOCAL -j SNAT -o %s --to-source %s" % (self.dev, cmdline.get_source_nat_ip())])
 
     def list(self):
         self.iplist = {}