What is an Active Directory?
Active Directory first introduced with Windows 2000 server. Active Directory allows administrators to create a more flexibility Network structure. Active Directory is a Directory services. Active Directory services are based approach to Network design it allows for large distributed network environment that have a common centralized authority for network security.
2> Active Directory provides a single point of management for Windows- based user account clients and application.
Domain tree: – In Windows 2000, a domain can be a child of another domain (e.g., child.domain.com is a child of domain.com). A child domain name always includes the complete parent domain name. A child domain and its parent share a two-way transitive trust. A domain tree exists when one domain is the child of another domain. A domain tree must have a contiguous namespace
Domain forest: – A forest is a collection of trees that don’t necessarily
form a contiguous namespace (although each tree must be contiguous). This arrangement might be useful if your company has multiple root DNS addresses.Each forest has admin Group. Members of the group have authority over all the Domain trees in the forest .Each domain has a Domain admin. Group and administrator in a parent Domain automatically transitive trust relationship .This type of structure is known as a hierarchical structured.
Why we need to Install Active Directory for Exchange server ?
Exchange server is fully integrated with AD.Exchange server Is a Prerequisite, it will not install unless AD is there
Installing Windows services by Exchange
Prior to Installing Exchange Server there are certain Windows Server 2003 components should be enabled on the server Because of level of integration Exchange has with active Directory and the windows Operating systems.
Following services should be enabled on the server.
1> Microsoft .NET frameworks.
2> Microsoft ASP.NET
3> World Wide Web services.
4> SMTP
5> NNTP
What services are installed as part of the Exchange Services?
Microsoft Exchange Event: – Monitors folders and files events for Microsoft Exchange Server.
Microsoft Exchange IMAP4 
rovides internet message access protocol 4 services to clients if this services is stopped clients are unable to connect to the computer using IMAP4
Microsoft Exchange information store :- manage the Microsoft Exchange information store including mailbox stores and public folder stores. If this service is stopped mail box stores and and public folder unavailable.
Microsoft Exchange Management: – Provides Exchange management information using Windows management integration. If this service is stopped exchange Management information is unavailable.
Microsoft Exchange POP3:- Provides POP3 topology services are used to connect mail services. If this services services stopped client can’t connect to the POP3 services.
Microsoft Exchange routing: – Provides topology and routing for Information to Exchange server. If this service is stopped optimal routing of Message will not will be available.
Exchange server services Dependency.
Services Dependency.
Microsoft Exchange Event Event Log, RPC
Microsoft Exchange IMAP4 IIS
POP3 IIS (admin)
Microsoft Exchange management RPC, Windows Management integration
Microsoft Exchange routing engine IIS admin
Storage technology
There are 2 types of storage technology we can offer on our Exchange server but the choice will depend on the Exchange server organization. We offer two types of external storage.
NAS (Network Address Storage)
1>Almost any machine that can connect to the LAN (or is interconnected to the LAN through a WAN) can use NFS, CIFS or HTTP protocol to connect to a NAS and share files.
2>A NAS identifies data by file name and byte offsets, transfers file data or file meta-data (file’s owner, permissions, creation data, etc.), and handles security, user authentication, file locking.
3>A NAS allows greater sharing of information especially between disparate operating systems such as Unix and NT.
4>File System managed by NAS head unit.
5>Backups and mirrors (utilizing features like NetApp’s Snapshots) are done on files, not blocks, for a savings in bandwidth and time. A Snapshot can be tiny compared to its source volume.
SAN (Storage Area Network)
A storage area network (SAN) is a type of local area network (LAN) designed to handle large data transfers. A SAN typically supports data storage, retrieval and replication on business networks using high-end servers, multiple disk arrays and Fibre Channel interconnection technology.
1>Only server class devices with SCSI Fibre Channel can connect to the SAN. The Fibre Channel of the SAN has a limit of around 10km at best.
2>A SAN addresses data by disk block number and transfers raw disk block.
3>File Sharing is operating system dependent and does not exist in many operating systems.
4>File System managed by servers
