GM: "Ok you get to the shaft where the guys disappeared to, you notice it is a smooth shaft that goes straight up into the mountain, doesn't appear to be any footholds on the sides."
Mage: "Ok I start levitating up the shaft with the group."
GM: "Ok that shaft goes on for a while, are you doing anything while you travel up?"
Mage: "I am assensing as I go, my spells are sustained through my Foci."
GM: "Ok, well you can see a ward is right in your way, what do you do?"
Now the mage has to either push through or break down the ward *which even if it is a weak one the caster of the ward will know if he pushes through or breaks it down* so the caster of the ward knows he is there. An alternate option is to go astral, and track down the caster of the ward, get his astral sig and change yours to match and have enough successes to beat the ward. He then can move through the ward with no issues since it will see him as the caster.