The IETF NEMO working group on network mobility is currently standardizing a basic support for moving networks. We need a handoff scheme for achieving the performance transparency during the movement of mobile routers in nested mobile networks. But the existed handoff schemes for a mobile host are not suitable for network mobility because packet transmission delay and traffic increase during mobile router’s handoff in nested mobile networks. This paper proposes a new seamless handoff scheme using the bi-casting based on IPv6 in nested mobile networks. Compared with the handoff schemes using bi-directional edge tunneling for host mobility support on simulation, the results show that the proposed handoff scheme reduces the packet delay during a mobile router changes the point of attachment in nested mobile networks.