Specific availability zones in a region are mapped per-account, so your east-1c might be my east-1a: "To ensure that resources are distributed across the Avail

Specific availability zones in a region are mapped per-account, so your east-1c might be my east-1a: "To ensure that resources are distributed across the Availability Zones for a region, we independently map Availability Zones to identifiers for each account. For example, your Availability Zone us-east-1a might not be the same location as us-east-1a for another account. Note that there's no way for you to coordinate Availability Zones between accounts." http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-reg...