What should I consider when assigning Site Link Costs in Active Directory

In Active Directory, the cost of a site link is a value that is used to determine the relative cost of replicating directory data over the link. Higher cost values are used for slower or more expensive links, while lower cost values are used for faster or less expensive links.
When assigning site link costs in Active Directory, you should consider the following factors:

Network Speed: The speed of the network connection between the sites is an important factor to consider when assigning site link costs. For example, a fast network connection such as a 1 Gbps Ethernet link would typically have a lower cost than a slower connection such as a T1 link.
Network Latency: The latency of the network connection between the sites is another important factor to consider when assigning site link costs. Higher latency can affect the performance of replication and should be taken into account when assigning costs.
Network Reliability: The reliability of the network connection between the sites is an important factor to consider when assigning site link costs. A connection with a high degree of reliability, such as a leased line, would typically have a lower cost than a connection with a lower degree of reliability, such as a dial-up connection.
Network Capacity: The capacity of the network connection between the sites is an important factor to consider when assigning site link costs. A connection with a high capacity, such as a fiber optic link, would typically have a lower cost than a connection with a lower capacity, such as a satellite link.
Network Distance: The physical distance between the sites is another factor to consider when assigning site link costs. Shorter distances typically result in lower costs due to lower latency and higher reliability.

By considering these factors, you can assign site link costs that accurately reflect the relative cost of replicating directory data between the sites. This can help to optimize the performance of Active Directory by routing replication traffic over the most efficient links.

Active Directory Infrastructure

Factors to consider when assigning Site Link Costs

1) Choose proportional cost values: Ensure that the cost values that you choose are proportional to each other

2) Choose proportional cost values. For example, if the connection from Seattle to Miami is twice as fast as the connection from Seattle to Denver

3) Choose proportional cost values: you should assign a cost value to the Seattle-Denver connection that is twice the value of the Seattle-Miami connection.

4) Plan for faster connections: Allow for faster connections than those you currently have when you choose your cost values.

5) In our example, you could assign a cost of 1 to the Seattle-Miami connection and a cost of 2 to the Seattle-Denver connection.

6) Build in flexibility: Adjust costs of existing links to accomodate new ones.

7) Build in flexibility: For example, if you added a link between Miami and Denver that was slower than the Seattle-Miami connection but faster than the Miami-Denver connection, you would adjust the costs of the existing links to accomodate the new link.