Research On Schemes Of Asymmetrical Path In The 6to4 Routing Domain

With the development of IPv6 network, IPv6 sites in the corner of the IPv4 Internethave demand to visit IPv6 backbone. Therefore, IETF NGTRANS workgroup discussmore transition technology, there are dual stack, tunnel and protocol translation. Alongwith one of tunnel,6to4 Tunnel ,We discuss 6to4 Router and 6to4 Relay Router and discussa problem of asymmetric paths in the 6to4 routing domain emphatically.Asymmetric path is a traffic depart from a router interface, but return the differentrouter. The 6to4 routing domain includes 6to4 router and 6to4 relay router. in the 6to4communication, the traffic may be the different paths in the both direction, we call theasymmetric paths in the 6to4 routing domain.There are a few reasons that discuss problem of asymmetric paths. First of all, the6to4 relay router spread around Internet dispersible. Forwarding and backing packets havedifferent delay as increasing distance of 6to4 router and 6to4 relay router. Thus transmitperformance gets influence like IP Phone traffic. Secondly 6to4 router suffer from attackDenial of Service easily, because there are security problem of asymmetric paths in the6to4 routing domain.In order to solve these problems at one time, we propose routing policy and policybased routing schemes to control the asymmetric paths. The routing policy scheme avoidinfluences of asymmetric path via change topology, announce routing and setting BGP4attribute. This is a scheme of control paths from macrocosm. In order to control the paths,the policy based routing scheme choose route via source address/destination address anduse mapping table. Simulation results confirm that applying these schemes in 6to4 routingdomain improves average throughout.