I'm looking at AWS Direct Connect options for a connection in Slough and noticed that the available choices include eu-west-1 and eu-west-2. Are these availability zones, or do they represent different AWS Regions? Does the choice affect latency, cost, or how I connect the circuit to my workloads?
3 Answers
For a Slough colocation, eu-west-2 is usually the intuitive option because it corresponds to the London Region. The other option is not a separate AZ in the same Region; it represents a different Region and may affect which resources and gateway associations are available. Check the Direct Connect pricing and your target VPC layout before choosing, since the cheaper option is not necessarily the most convenient one.
The important factor is where your workloads are and how you plan to use the connection. If you’re associating a virtual interface directly with a VPC through a virtual private gateway, the Region matters, so you’d normally choose the Region containing that VPC. If you’re using a Direct Connect gateway, you have more flexibility because it can provide access to VPCs in other Regions.
Those entries are Regions, not Availability Zones. Availability Zones would have names such as eu-west-1a or eu-west-2b. For Direct Connect, the Region refers to the AWS control-plane association for the connection location. eu-west-1 is Ireland, while eu-west-2 is London.
So for workloads primarily in London, eu-west-2 would generally be the natural choice, while eu-west-1 would make more sense for resources in Ireland.