It's hard to tell what you are trying to do. Can you provide more details? Are you trying to set up a VPN with the 130, or just use it as an Ethernet switch?
The cable modem is connected to to the DIR130. So the DIR130 is acting as a router to the internet? Then how are you trying to use the DIR825? Usually you'd have only one router, unless you are disabling the router features on one of them.