In us-east-1? That doesn't sound that impactful, have always heard that us-east-1's network is a ring.
Back before AWS provided transparency into AZ assignments, it was pretty common to use latency measurements to try and infer relative locality and mappings of AZs available to an account.
Back before AWS provided transparency into AZ assignments, it was pretty common to use latency measurements to try and infer relative locality and mappings of AZs available to an account.