ISTG what happens when it Fails ? 当ISTG角色失败，会发生什么

以下是搜索到关于ISTG角色失败相关的文档，文档的结论就是当ISTG角色失败的时候，在站点中会自动从新分配另外一台域控制器成分ISTG

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http://blogs.technet.com/b/janelewis/archive/2009/05/07/istg-what-happens-when-it-fails.aspx

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I had an interesting investigation the other day with a customer of mine with reference to the role and failover of the ISTG role.

In the customers scenario they switch off the ISTG and several other servers in a very busy site to simulate a outage scenario. This site is a main hub site in a very large enterprise environment Forest and has in excess of 200 sites hanging off it. Many of these sites are empty many have just 1 or 2 Domain Controllers in there.

So what should happen ?     ISTG一段时间不可用的结论如下

When a Server that holds the ISTG is unavailable for a period of time then there is an inbuilt automated process which the Servers within the site go through to re-allocate this role to another server. The checking for the existence of a ISTG will effectively happen every 15 minutes as part of the KCC process.

我测试结果当站点中一台域控制器，同时是ISTG和桥头服务器的时候，在其宕机的情况下，只要此站点有另外一台域控制器正常，那么这两个角色都会自动转移。