Restricting access on Wlan1

[Dice]

Small question :

I have a Mark V;

i am using Wlan1 to get a clientbased connection to a known Wifi Network.

I want to be able to restrict the access for Wlan1 to the default gateway and Internet; eg Not being able to access anything on the internal side of that router;

Doing some research i was pointed towards IPtables; now i need a way to set those rules to Wlan1.

is there any infusion which will allow me to restrict that Wlan1 ?

Knd rgds

../Dice