Moving DNS out of non-cooperative provider

Phil Mayers p.mayers at imperial.ac.uk
Mon Jun 18 16:13:10 UTC 2012


On 18/06/12 16:49, Alexander Gurvitz wrote:

> with each query gets new NS record, and... refreshes the NS TTL ?

No, that's not how TTLs work. They always count down.

>
> Will ns.isp.com <http://ns.isp.com> EVER query ns.NEWprovider.net
> <http://ns.NEWprovider.net> ?

Yes, when the TTL has expired.

>
> I'd be happy to know how BIND behaves, but also
> how other servers may behave in this case.
>

This isn't server-specific; every DNS server should behave this way.

The only way a recursive server will continue to see the old record is 
if the recursive server either forwards to the "old" provider, or slaves 
the old provider zone - this might happen if the recursive server is 
owned by the same ISP as the "old" authoritative server.



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