No soldiers were injured when shots were fired at the checkpoint near Kunduz around 8 pm on Friday, and officials are investigating the incident.
The military did not confirm whether Bundeswehr soldiers returned fire or injured insurgents in the attack.
Germany currently has some 3,500 troops stationed in northern Afghanistan who have become the target of an increasing number of insurgent attacks as part of the NATO International Security Assistance Force (ISAF) mission there.
A suicide attack near Kunduz killed two German troops and five Afghan children on October 20, as a man blew himself up after approaching the German soldiers on a bicycle.
The Islamist Taliban claimed responsibility for the attack against "invasion troops" hours after incident.
This month the German Bundestag, or lower house of parliament, voted to extend Germany's participation in Afghanistan and increase the number of soldiers deployed there to 4,500.