Toggle DNS Check seems to be confusing word but after drilling down you will notice that its same as allowing auto configured DNS ( example 0.0.0.0) and allowing custom DNS (u.x.y.z). In android mobile phones you can easily perform this task as i described earlier in updating SMSC no in Android . You just need to use master testing code for android phones i.e  dial this code from your phone *#*#4636#*#*

Some screen shots of the test performed on Samsung GalaxyS are as follows

Toggle DNS Check

Toggle DNS check How to Toggle DNS Check in Android Mobiles

Update DNS Check

Toggle DNS checkp allowed How to Toggle DNS Check in Android Mobiles