This paper describes the design and implementation of an IPv6 multicast forwarder as the preliminary step for developing a high-speed IPv6 multicast-enabled router for use in an environment where multicast packets occupy some portion of the total network traffic using the programmable IXP2400 network processor. We validate our implementation and evaluate its performance with hardware experiments. Our experimental results show that the measured forwarding rate is 86% of full line rate in the minimum IPv6 packet size and the latency of IPv6 multicast packet forwarding compared with IPv6 unicast increases 25% in average. These are due to the processing overhead of IPv6 multicast route lookup in IPv6 Multicast Forwarder microblock, the packet copy in Packet Replication microblock, and the packet buffer management in Packet TX microblock1.