Comment 9 for bug 1649317

Here are some other relations (on port, router and subnet objects) that may be the root causes for the same problem.

subnet <-> subnetpool <-> subnetpoolprefixes
       <-> ipallocationpools
       <-> dnsnameservers
       <-> subnetroutes
       <-> network_rbacs
       <-> subnetservice_types

port <-> ipallocations
     <-> allowedaddresspairs
     <-> subports
     <-> extra_dhcp_opts
     <-> trunks <-> subports
     <-> securitygroupportbindings
     <-> portdnses

router <-gw-> port (gateway_port)
       <-> routerroutes
       <-> routerl3agentbindings