What is a site, the Xi. Active directory series

What is a site

When it comes to sites in Active Directory, many Active Directory beginners will have a deep headache. It's not clear what the site is doing. A lot of students have asked such a question, site and domain what is the difference? In the end is the domain big or the site big? Why do I have a site if I have a domain? ... this article will try to introduce the concept of site and design the original intention, so that everyone can better understand the site, the use of the site.

A domain is a group of computers that share user accounts, computer accounts, and security policies, and this definition is based on logical considerations, so long as users and computers are in the same Active Directory, we assume they are within the security boundaries of the domain. We can see from the definition of the domain that the domain does not take into account the network speed and other physical factors, regardless of whether the computer and the domain controller is a fast physical connection or a slow physical connection, the domain will be the same, completely the connection speed as if nothing. But in the actual production environment we will find that if we do not consider the physical factors such as network speed, we will encounter a lot of trouble in admin domain. We illustrate by an example, as shown in the following figure, a domain controller is distributed in Beijing, Shanghai Two, Beijing has a,b,c three domain controllers, Shanghai has d,e,f three domain controllers. Beijing and Shanghai's local LAN are gigabit Ethernet, between Beijing and Shanghai is a 128K line.