[dns-operations] aws.amazon.com zone has only one nameserver

[Phil Regnauld]

Yonghua Peng (pyh) writes:
> ~$ idig aws.amazon.com ns
> aws.amazon.com.         587     IN      NS      ns-911.amazon.com.
> 
> ~$ idig aws.amazon.com soa
> aws.amazon.com.         60      IN      SOA     ns-911.amazon.com.
> root.amazon.com. 1449536989 3600 900 7776000 60
> 
> ~$ idig ns-911.amazon.com
> ns-911.amazon.com.      197     IN      A       207.171.178.6

    My first query returned:

    aws.amazon.com.     5126    IN  NS  ns-923.amazon.com.
    aws.amazon.com.     5126    IN  NS  ns-912.amazon.com.
    aws.amazon.com.     5126    IN  NS  ns-931.amazon.com.
    aws.amazon.com.     5126    IN  NS  ns-921.amazon.com.
    aws.amazon.com.     5126    IN  NS  ns-911.amazon.com.
    aws.amazon.com.     5126    IN  NS  ns-932.amazon.com.

    After that I get changing NS records, 1 NS in the RR set / query:

    aws.amazon.com.     486 IN  NS  ns-924.amazon.com.

    aws.amazon.com.     488 IN  NS  ns-911.amazon.com.

    aws.amazon.com.     539  IN  NS  ec2-52-19-138-45.eu-west-1.compute.amazonaws.com.

    aws.amazon.com.     534 IN  NS  ns-945.amazon.com.

    I think they're doing a mix of geolocation and possibly anycast - but
    hostname.bind doesn't return anything here.

    Either way, I think they know what they're doing, and there's definitely
    more than 1 NS instance behind each IP :)

    Cheers,
    Phil