You are asking the wrong people here. Go ask your switch vendor to send an IP address as part of the authentication. Please make sure to forward a copy of their response to this list.
I understand it. And along to it I started some ight duscussion of one of switch (amanged one) representatives to add such funtional for it. And I asked this quiestion here because this case is two side - server (Freeradius) and switch where server send out simply "yes" or "no" that is it gives an order to a switch "yes" or "no" and a switch simply ececute it - to allow or to deny access. And if such functional is at switch but is not at server (Radius) , it will not work at all. That is if switch is able to send port:mac:IP but Freeradius can not accept of such data and can not further handle it in a right way, such functinality will not work. One more, I tried to ask both "sides" - server developers/community and switch maker (one of brand) personell as well.