If you are using Amazon Route 53 as your public, authoritative DNS, you will now have the capability to easily log DNS queries received by Amazon Route 53 through integration with CloudWatch Logs.
For example, suppose you have EC2 instances in the AWS US East (Ohio) region and in the US West (Oregon) region. When a user in Los Angeles browses to your website, geoproximity routing will route the DNS query to the EC2 instances in the US West (Oregon) region because it's closer geographically. If you want a larger portion of users in the middle of the United States to be routed to one region, you can specify a positive bias for that region, a negative bias for the other region, or both.
On March 8, 2017, the Certification Authority and Browser Forum (CA/Browser Forum) mandated that by September 8, 2017, CA’s are expected to check for the presence of a CAA DNS record and, if present, refuse issuance of certificates unless they find themselves on the whitelist <https://cabforum.org/2017/03/08/ballot-187-make-caa-checking-mandatory/>.
DNS CAA 可以設定哪些 SSL certificate 可以發出你的證書,除了自己以外,也可以讓第三者比較容易確認是否有誤發的行為:
We have seen a lot of interest in Amazon Route 53 support for Certification Authority Authorization (CAA) records, which let you control which certificate authorities (CA) can issue certificates for your domain name.
However, most browsers have implemented their own caching layer that can override the TTL specified by the server. In fact, some browsers cache for 5-10 minutes, which is an eternity when a region or data center fails and you need to route end users to a different location.