终于快要完成DNS and BIND的翻译了
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2008/07/05 .. by Rico
2008/07/05 .. by Rico
DNS and BIND 第十七章 杂项
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2008/07/04 .. by Rico
2008/07/04 .. by Rico
"The time has come," the Walrus said, "To talk of many things: Of shoesand shipsand sealing-waxOf cabbagesand kingsAnd why the sea is boiling hotAnd whether pigs have wings."
终于到尾声了。前面谈过DNS和BIND的维护,还有一些不错的技巧尚未探索,比如Active Directory如何与BIND协作等。让你学业未成就下山可没良心!
17.1. 使用CNAME记录
17.1.1. 附加到内部节点的CNAME
由于单位重组需要对区重命令,可以考虑创建一个CNAME记录,以将旧的域名指向新的域名。比如,如果fx.movie.edu要改成magic.movie.edu,可能忍不住弄条CNAME记录将所有旧的域名都指向新的域名:
fx.movie.edu. IN CNAME magic.movie.edu.
DNS and BIND 第十六章 布局
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2008/07/04 .. by Rico
2008/07/04 .. by Rico
"Now if you'll only attend, Kitty, and not talk so much, I'll tell you all my ideas about Looking-glass House."
回顾一下前面陆续为电影学院配置的域名服务器结构:第4章建立了首台主域名服务器及从服务器;第9章创建子域并委派子域服务器;第11章引进对外服务器及转发器、分割域名空间、视图等。为形成完整的概念,本章研究如何构建DNS布局。
DNS布局更重视的是所有域名服务器的整体配置。哪台为主,哪台为从?如何解析互联网域名?转发器设在哪?转发谁的查询?哪台上要设置ACL和防火墙,并且要保护谁?
你应当将设计的DNS布局记下来,如设计网络拓扑一样。此文档可以帮助你快速定位问题点、性能瓶颈及安全漏洞。出现问题时看此结构图比逐个研究named.conf和dig的输出要高效的多。
然而,一次概括出完整的DNS布局难度不小。我们首先看一下其中的片段:对外、授权域名服务器。
DNS and BIND 第十五章 解析器和域名服务器库编程
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2008/07/03 .. by Rico
2008/07/03 .. by Rico
"I know what you're thinking about," said Tweedledum; "but it isn't so, nohow."
"Contrariwise," continued Tweedledee, "if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic."
"Contrariwise," continued Tweedledee, "if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic."
我打赌你认定解析器编程非常难。恰好相反!其实并没那么难。DNS消息的格式非常直接;你根本不用处理ASN.1,不像SNMP一样。并且有解析DNS消息的很棒的库。Appendix A包含有部分RFC 1035的内容,不过阅读本章时如果手边有RFC 1035参照着当然更好,DNS编程时更加需要它。
ASN.1为Abstract Syntax Notation。ASN.1为编码对象类型的方法,被International Organization for Standardization收为互联网标准。
15.1. Shell脚本调用nslookup编程
可以用shell脚本编写调用nslookup或者dig的程序,好处如下:
● 比C程序写得快。
● 重点关注DNS基本功能。C程序重点关注附加控制。
● shell版本的程序足以解决你的任务,维护也很容易。
DNS and BIND 第十四章 DNS和BIND故障排除
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2008/07/01 .. by Rico
2008/07/01 .. by Rico
"Of course not," said the Mock Turtle. "Why, if a fish came to me, and told me he was going on a journey, I should say, `With what porpoise?'"
"Don't you mean `purpose'?" said Alice.
"I mean what I say," the Mock Turtle replied, in an offended tone. And the Gryphon added, "Come, let's hear some of your adventures."
"Don't you mean `purpose'?" said Alice.
"I mean what I say," the Mock Turtle replied, in an offended tone. And the Gryphon added, "Come, let's hear some of your adventures."
前面两章,我们示范如何使用nslookup和dig,及如何阅读域名服务器调试信息。本章我们将用这些工具加上Unix网络工具(如ping)来处理实际中出现的DNS及BIND的故障。
故障维护天生就很难教。症状千变万化却要找到病因,我们不可能覆盖你遇到的全部问题,不过可以尽力示范如何诊断其中最常见的问题,更重要的是教会你们故障维护的技巧,这对你查找别的更隐藏的问题应当是很有价值的。





