Comment by mayli

Latest github NS moved to awsdns

        $ dig -tNS github.com @8.8.8.8

        ; <<>> DiG 9.8.3-P1 <<>> -tNS github.com @8.8.8.8
        ;; global options: +cmd
        ;; Got answer:
        ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15616
        ;; flags: qr rd ra; QUERY: 1, ANSWER: 8, AUTHORITY: 0, ADDITIONAL: 0

        ;; QUESTION SECTION:
        ;github.com.                    IN      NS

        ;; ANSWER SECTION:
        github.com.             899     IN      NS      ns-1283.awsdns-32.org.
        github.com.             899     IN      NS      ns-1707.awsdns-21.co.uk.
        github.com.             899     IN      NS      ns-421.awsdns-52.com.
        github.com.             899     IN      NS      ns-520.awsdns-01.net.
        github.com.             899     IN      NS      ns1.p16.dynect.net.
        github.com.             899     IN      NS      ns2.p16.dynect.net.
        github.com.             899     IN      NS      ns3.p16.dynect.net.
        github.com.             899     IN      NS      ns4.p16.dynect.net.

        ;; Query time: 32 msec
        ;; SERVER: 8.8.8.8#53(8.8.8.8)
        ;; WHEN: Fri Oct 21 13:01:48 2016
        ;; MSG SIZE  rcvd: 248

But my local copy is still on dynect

        $ dig -tNS twitter.com

        ; <<>> DiG 9.8.3-P1 <<>> -tNS twitter.com
        ;; global options: +cmd
        ;; Got answer:
        ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62729
        ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 4

        ;; QUESTION SECTION:
        ;twitter.com.                   IN      NS

        ;; ANSWER SECTION:
        twitter.com.            75575   IN      NS      ns3.p34.dynect.net.
        twitter.com.            75575   IN      NS      ns4.p34.dynect.net.
        twitter.com.            75575   IN      NS      ns1.p34.dynect.net.
        twitter.com.            75575   IN      NS      ns2.p34.dynect.net.

        ;; ADDITIONAL SECTION:
        ns3.p34.dynect.net.     54698   IN      A       208.78.71.34
        ns4.p34.dynect.net.     81779   IN      A       204.13.251.34
        ns1.p34.dynect.net.     8544    IN      A       208.78.70.34
        ns2.p34.dynect.net.     54775   IN      A       204.13.250.34

        ;; Query time: 0 msec
        ;; SERVER: <local>
        ;; WHEN: Fri Oct 21 13:02:14 2016
        ;; MSG SIZE  rcvd: 179