In conntrack SNAT when an NAPT switch is selected on a compute without any port in the router subnet not all necessary fob flows are programmed.

Steps to reproduce.

1)Create an external n/w and external subnet.
2)Create a router and and set the g/w( NAPT switch should be selected on a compute withour any router subnet. If not new router can be create until this is achieved.
3)Create an internal subnet and add to the router.

Expected Output.
FIB flows to direct the packet to DHCP NS should be present in the NAPT switch

Actual Output
FIB flows are not present always.