Whenever a last VM part given VRF is deleted/migrated, it is required to delete 'dpn-vpninterfaces-list' entry for given dpn-id from 'odl-l3vpn:neutron-router-dpns' Operational DS. This trigger re-election of new Napt Switch which has VRF presence. But, when 2 VMs part of
same VRF on a same DPN deleted simultaneously, then there are chances that both of these event doesn't delete 'dpn-vpninterfaces-list' entry for the DPN which results in non-triggering on new Napt Switch election. As a result, the SNAT reverse traffic initiated from Non-Napt Switch fail as FIB routes will not be available to carry back traffic to non-napt switch.