If you mean restrict port forwarding to be from certain named WAN IP addresses then I am afraid VM hubs do not offer this facility. Certain other routers do offer this. VM hubs are locked down a lot to stop users changing them in the misguided belief that people will muck up their connection or that the call centre operators will not be able to understand what has been changed.
Tudor
There are 10 types of people: those who understand binary and those who don't and F people out of 10 who do not understand hexadecimal c1a2a285948293859940d9a49385a2