update iptables rules for more useful debugging

As discussed with dansmith in #openstack-nova,
iptables --line-numbers -L -nv is a more useful representation of
the iptables dump for determining network issues.

Related-Bug: #1298472

Change-Id: Ibae97f7a0cf29105e3601eca8ce24b8271a3a13d
diff --git a/tempest/common/commands.py b/tempest/common/commands.py
index 6720847..2ab008d 100644
--- a/tempest/common/commands.py
+++ b/tempest/common/commands.py
@@ -50,7 +50,7 @@
 
 
 def iptables_raw(table):
-    return sudo_cmd_call("iptables -v -S -t " + table)
+    return sudo_cmd_call("iptables --line-numbers -L -nv -t " + table)
 
 
 def ip_ns_list():
diff --git a/tempest/tests/test_commands.py b/tempest/tests/test_commands.py
index bdb9269..1e2925b 100644
--- a/tempest/tests/test_commands.py
+++ b/tempest/tests/test_commands.py
@@ -47,7 +47,8 @@
     @mock.patch('subprocess.Popen')
     def test_iptables_raw(self, mock):
         table = 'filter'
-        expected = ['/usr/bin/sudo', '-n', 'iptables', '-v', '-S', '-t',
+        expected = ['/usr/bin/sudo', '-n', 'iptables', '--line-numbers',
+                    '-L', '-nv', '-t',
                     '%s' % table]
         commands.iptables_raw(table)
         mock.assert_called_once_with(expected, **self.subprocess_args)