Afghan and Pakistani forces traded fire last week, a matter which escalated significantly over the weekend, with Pakistan reportedly killing 50 Afghan troops and destroying multiple checkpoints. The matter started over a dispute on where the border is, and Pakistani census workers trying to work along the frontier.
A deal is in place to resolve the situation according to both Afghan and Pakistani officials, following an agreement to use Google Maps and GPS tracking to settle exactly where the Durand Line border is. The Durand Line has been the de facto border between Afghanistan and Pakistan since 1947.
It's disputed by some in Afghanistan, however, who argue that the Indus River is the real border. The consequences of this claim would be that Afghanistan would own most of Pakistan, and needless to say that's never going to actually happen. Afghanistan's government largely respects the Durand Line.