[dns-operations] bit.ly serial number (and content) desynchronisation

[Dave Lawrence]

Chris writes:
> It's also interesting to note the wide range in the
> caches -- 3600 - 86400.


> bit.ly.	3600	IN	NS	ns-cloud-c2.googledomains.com.
> bit.ly.	3600	IN	NS	ns-cloud-c3.googledomains.com.
...
> bit.ly.	86400	IN	NS	ns-cloud-c2.googledomains.com.
> bit.ly.	86400	IN	NS	ns-cloud-c3.googledomains.com.

This part isn't that surprising.  The delegating NS RRset is one hour,
and probably standard across all .ly domains.  (I'm not aware of a
registry that uses varying TTLs for different delegations, but it's
possible.)

The one day TTL comes from the authoritative NS RRset.