Question

You have a network consisting of three sites and 15 member servers. Both SiteA and SiteB have six of the member servers, and SiteC has three member servers. SiteA and SiteB are across town from each other, and SiteC is in another state. Your environment is heavily virtualized, with Hyper-V running on 4 servers each in SiteA and SiteB and a total of 24 VMs spread evenly among the servers. Each server is capable of running double the number of VMs it’s currently running. Hyper-V is running on two servers in SiteC. SiteC isn’t currently running any VMs, but Hyper-V is installed on the servers for contingency purposes. The SiteC servers are capable of running all 24 VMs, if necessary.

describe a server and site disaster recovery plan.

Include features of Windows Server 2012 R2 that should be used in your plan. Be sure to include the following elements: Clustering, if any, including the quorum configuration Virtual machine fault-tolerance strategies, such as live migration and Hyper-V replicas Windows Server Backup and Microsoft Azure Backup, if necessary

Answer 1

Active directory implements a replication topology that takes advantage of the network speeds within sites, while are ideally configured to be equivalent to local area nerwork(LAN) connectivity (network speed of 10 megabits per second [MBPS] or higher). The replication topology also minimizes the use of potentially slow or expensive wide area network (WAN) links between sites.

When you create a site object in Active Directory, you associate one or more Internet Protocol (IP) subnets with the site. Each domain controller in a forest is associated with an Active Directory site. A client workstation is associated with a site according to its IP address; that is, each IP address maps to one subnet, which in turn maps to one site.

Active Directory uses sites to:

• Optimize replication for speed and bandwidth consumption between domain controllers.
• Locate the closest domain controller for client logon, services, and directory searches.
• Direct a Distributed File System (DFS) client to the server that is hosting the requested data within the site.
• Replicate the system volume (SYSVOL), a collection of folders in the file system that exists on each domain controller in a domain and is required for implementation of Group Policy.

The ideal environment for replication topology generation is a forest that has a forest functional level of at least Windows Server 2003. In this case, replication topology generation is faster and can accommodate more sites and domains than occurs when the forest has a forest functional level of Windows 2000. When at least one domain controller in each site is running Windows Server 2003, more domain controllers in each site can be used to replicate changes between sites than when all domain controllers are running Windows 2000 Server.

In addition, replication topology generation requires the following conditions:

• A Domain Name System (DNS) infrastructure that manages the name resolution for domain controllers in the forest. Active Directory–integrated DNS is assumed, wherein DNS zone data is stored in Active Directory and is replicated to all domain controllers that are DNS servers.
• All physical locations that are represented as site objects in Active Directory have LAN connectivity.
• IP connectivity is available between each site and all sites in the same forest that host operations master roles.
• Domain controllers meet the hardware requirements for Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Standard Edition; Windows Server 2003, Enterprise Edition; and Windows Server 2003, Datacenter Edition.
• The appropriate number of domain controllers is deployed for each domain that is represented in each site.

This section covers the replication components that create the replication topology and how they work together, plus the mechanisms and rationale for routing replication traffic between domain controllers in the same site and in different sites.

Active Directory KCC Architecture and Processes:

The replication topology is generated by the Knowledge Consistency Checker (KCC), a replication component that runs as an application on every domain controller and communicates through the distributed Active Directory database. The KCC functions locally by reading, creating, and deleting Active Directory data. Specifically, the KCC reads configuration data and reads and writes connection objects. The KCC also writes local, nonreplicated attribute values that indicate the replication partners from which to request replication.

For most of its operation, the KCC that runs on one domain controller does not communicate directly with the KCC on any other domain controller. Rather, all KCCs use the knowledge of the common, global data that is stored in the configuration directory partition as input to the topology generation algorithm to converge on the same view of the replication topology.

Each KCC uses its in-memory view of the topology to create inbound connections locally, manifesting only those results that apply to itself. The KCC communicates with other KCCs only to make a remote procedure call (RPC) request for replication error information. The KCC uses the error information to identify gaps in the replication topology. A request for replication error information occurs only between domain controllers in the same site.

ne domain controller in each site is selected as the Intersite Topology Generator (ISTG). To enable replication across site links, the ISTG automatically designates one or more servers to perform site-to-site replication. These servers are called bridgehead servers. A bridgehead is a point where a connection leaves or enters a site.

The ISTG creates a view of the replication topology for all sites, including existing connection objects between all domain controllers that are acting as bridgehead servers. The ISTG then creates inbound connection objects for servers in its site that it determines will act as bridgehead servers and for which connection objects do not already exist. Thus, the scope of operation for the KCC is the local server only, and the scope of operation for the ISTG is a single site.

Each KCC has the following global knowledge about objects in the forest, which it gets by reading objects in the Sites container of the configuration directory partition and which it uses to generate a view of the replication topology:

• Sites
• Servers
• Site affiliation of each server
• Global catalog servers
• Directory partitions stored by each server
• Site links
• Site link bridges