http://note.youdao.com/noteshare?id=7898fa39596740bfcc9ca42ad643f045&sub=28A00029E566426A89F3ADBC11B2442C
word版本下载
http://down.51cto.com/data/2449141
Linux实战第九篇：基于Centos6.9+7.4主备DNS服务器搭建实战
原文：http://blog.51cto.com/6575793/2140483
