[ovs-discuss] why ct_snat in gateway router without recirc_table

[Wei Li]

Hello everyone

In 
https://github.com/openvswitch/ovs/blob/master/ovn/lib/actions.c?utf8=%E2%9C%93#L833 


} else if (snat && ep->is_gateway_router) {
         /* For performance reasons, we try to prevent additional
          * recirculations.  ct_snat which is used in a gateway router
          * does not need a recirculation.  ct_snat(IP) does need a
          * recirculation.  ct_snat in a distributed router needs
          * recirculation regardless of whether an IP address is
          * specified.
          * XXX Should we consider a method to let the actions specify
          * whether an action needs recirculation if there are more use
          * cases?. */
         ct->recirc_table = NX_CT_RECIRC_NONE;
     }

but in 
https://github.com/openvswitch/ovs/blob/master/ovn/northd/ovn-northd.8.xml?utf8=%E2%9C%93#L1390

         <p>
           If the Gateway router has been configured to force SNAT any
           previously DNATted packets to <var>B</var>, a priority-110 flow
           matches <code>ip &amp;&amp; ip4.dst == <var>B</var></code> with
           an action <code>ct_snat; next;</code>.
         </p>


Action "ct_snat" already include "resubmit next table", why delete it 
and add a "next" action?

What is the difference between "ct_snat without recirc_table and next" 
and "ct_snat with recirc_table"?


Thanks in advance