Study Of The DNS In IPv4/IPv6 Co-exist Network

In recent years, because of the problem of the exhaustion of IPv4 address, the lack of netid, and the fast expansion of routing table, IPv6 turns up.Compared with IPv4, IPv6 has got security mechanism naturally, and strengthens support to multicast, etc. What's important is IPv6 supplies huge address space. All of its advantages indicate that IPv6 will take place of IPv4 to be the core of NGI.However, there may be a long time to update Internet from IPv4 to IPv6. The IPv4 will co-exist with IPv6 in a long time. During this period, a good transition mechanism not only is effective scheme to keep communication between two kinds of network but also is the key of transiting IPv4 to IPv6 smoothly.DNS is the key application of IPv4 network, as well as IPv6 network. The main problem for us is to choose the perfect transition mechanism of DNS during the transition of IPv4 to IPv6.In the condition of IPv4 co-exist with IPv6, the thesis focuses on study the DNS of IPv4,DNS of IPv6,IPv6 technology, and the technology of updating network from IPv4 to IPv6. We implement three designs of DNS in campus network which IPv4 network co-exists with IPv6 expriment network by several transition technology. The main work is system model designing, network environment designing, DNS database designing. Design double stack and IPv6 database of DNS. Additionally, in the solution designing of translating mechanism, we code a domain name access system which enable IPv4 host to access IPv6 DNS server base on IPv6 socket technology. At last, we have a test on three solutions to DNS system, and discuss the features and the suitable environment of the solutions by technology analysis.As the result, we should choice the best solution to DNS problem during period of transition process based on different conditions.