🔗AD Site and Site-Links

Idea of Site & Stie-Links

Active Directory sites

Idea of Site and Site Links

1. The Active Directory site defines a physical topology of the network. Sites can be separate buildings in a campus network, with the branch office in a separate city or even in a separate country.

2. Active Directory Sites are logical groupings of IP subnets that reflect physical network locations, like offices or campuses. They ensure clients connect to nearby domain controllers (DCs) for faster authentication and reduce WAN traffic.

3. AD sites are used for managing organizations that have branches spread across different geographical locations but fall under the same domain. It is a robust solution to geographically manage an AD network without changing any aspect of the logical structure of the environment. AD sites are physical groupings of well-connected IP subnets that are used to replicate information among domain controllers (DC) efficiently

What are subnets

A subnet (short for "subnetwork") is a logical subdivision of an IP network. In Active Directory (AD), subnets are used to group computers based on their IP addresses and physical location on the network. In Active Directory, a site is made up of one or more subnets that are well-connected (have fast and reliable network connectivity between them).

AD Site Links

Site Links are connections between sites that control how AD data replicates across locations. They have properties like cost (priority for replication) and schedule (when replication happens), helping manage bandwidth usage.

Active Directory Replication

1. Replication in Active Directory ensures that all Domain Controllers (DCs) across different locations have consistent and up-to-date data (user accounts, group policies, passwords, and more Configuration ) Within the same Domain.

2. AD is a multi-master database – any DC can be updated, and those changes need to be copied (replicated) to all other DCs.

Intra-site Replication Types

Intra-site Replication

Intra-site replication happens within the same site, using high-speed LAN connections. When a change occurs, the domain controller waits 15 seconds by default before notifying others, ensuring quick updates. This process is event-driven, not on a fixed schedule, making it ideal for local networks, That happen Within DCs in the same Domain.\

Inter-site Replication

Inter-site replication connects different sites, often over slower WAN links. It’s scheduled, with a default of every 3 hours, but can be set to as little as 15 minutes. Administrators might schedule it for off-peak times, and data is compressed to save bandwidth, using bridgehead servers for efficiency.