nih.gov NS only answers TCP queries

[Stephane Bortzmeyer]

On Mon, Mar 03, 2025 at 09:54:46AM -0500,
 Keith Mitchell <keith at dns-oarc.net> wrote 
 a message of 33 lines which said:

> There was much social media speculation over the weekend that this was a 
> DNS issue, but it seems a lot of NIH online infrastructure was taken 
> down without too much heed for the side-effects.

The fact that the authoritative name servers replied with TCP but not
with UDP, seem to indicate that:

* it was not a layer-3 (or 1 or 2) issue,
* the DNS software was still up.

My guess would be some amateur reviewing the configuration of the
firewall and saying "everybody knows that UDP is dangerous, let's
block it".