i have a tp link wireless router that i am having trouble setting domain name filtering on

It is currently connected to my dynalink rta1025w wireless modem/router that i purchased from my isp

I have tried setting up domain name filtering in my tp link router.

my tp link router is connected to my dynalink modem/router via the lan connection on the dynalink one to the lan on the tp link one

They have different ssids are on different chanels and have a different security key?

Why aint domain name filtering working?