[dns-operations] Concerns regarding the ICANN/IANA DNS vulnerability checker

Simon Waters simonw at zynet.net
Tue Aug 19 11:25:44 UTC 2008

On Tuesday 19 August 2008 11:30:26 Mohsen Souissi wrote:
> For example:
>  - "dig @[fz].nic.de de ns"
>  - "dig @ca0[1-6].cira.ca ca ns"
>  - "dig @[a-m].gtld-servers.net net ns"
> all have the same behavior as a.nic.fr (if I'm not wrong) as they are
> not authoritative for the child zone in which sits the NS. The list of
> examples may be quite long I guess, that's not the point.

The TTL for the additional results from A.NIC.FR decrease.

The TTL for the additional results from f.nic.de don't (although I get 
different results at different times from f.nic.de, so I assume it is more 
than one servers - version queries suggest something similar).

So I doubt the configurations are identical. 

Let us call them superficially similar ;)

> Is that considered a bad idea?
> Please justify whether the answer is YES or NO.

Can your cached data be corrupted by spoofing? 

If "yes" then it is a bad idea. 

As to whether supplying additional answers that are "nothing to do with you" 
is a good idea; I'd think most are ignored (burning bandwidth to no avail, 
and when they aren't being ignored they risk being wrong). I think a lean DNS 
config is probably the thing.

I note my DNS servers serve additional data from other zones they are 
authoritative for, so I probably ought to stop that as well for similar 

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