Abstract: A method and system for data packet forwarding is provided. A forwarding information base is stored. The forwarding information base has a first stage with a first lookup key and a second stage with a second lookup key. The first lookup key is a portion of the second lookup key. The first stage is evaluated using the first lookup key forwarding the data packet is forwarded if the first stage evaluation yields a forwarding result. If the first stage evaluation does not yield a forwarding result, the second stage is evaluated using the second lookup key to determine a forwarding result. Such a method and system are suitable for use, among other places, in a network processing unit (“NPU”) in an IPv6 network.