Design And Implementation Of DNS Proxy On High Concurrency Router Platform

Domain Name System is the one of the most important services of the Internet. Itcan be mutual mapping between the domain name and IP address resolution services. Thedomain name system provides a convenient way for Internet user. Domain nameresolution technology has become an important part of the Internet. However, many of thesystem’s performance and security defects have been exposed due to the origin of DNS,many types of network attacks, leaving the classic case of network security in the longhistory, simply because of its enormous destructive power and a wide range of influence.Cause a great threat to them in the context of the information society and national security,the current network.When using DNS in LAN, through setting up a DNS proxy server in the gatewayrouter, the network administrator can deal with performance and secure problem byconfiguring the DNS proxy server. Meanwhile, a DNS proxy can improve the cacheinquires shooting rate, thus achieve more efficient resolution services.In this thesis, based on the basic principle of DNS protocol and proxy server, throughstudy the DNS cache mechanism and research proxy server problems in practicalapplication, the author design a DNS proxy cache data management mechanism, whichcan achieve high efficiency of cache inquires and timeout deleting, meet the requirementof command line tool to obtain a dictionary sequence table list of DNS host entry, andkeep high performance with large cache, at the same ensure data consistency underConcurrent operating. In additional, a cache configuration recovery plan is given, reducingimpacts of system accidents.Test scheme and test results of the system are given at last. The test proves that designscheme of the system meet the function requirement and performance requirement.Applications and products developed with the scheme have passed the acceptance andbegin to be accepted by market, and have a broad prospect of application.