[nsd-users] enable-minimal-responses

[Todd Rinaldo]

On Nov 23, 2011, at 4:17 AM, Matthijs Mekking wrote:

> RELNOTES
> ========
> 
> FEATURES:
> - - Minimize responses to reduce truncation: NSD will only add optional
>  records to the authority and additional sections when the response
>  size does not exceed the minimal response size.
> 
>  The minimal response size is 512 (no-EDNS), 1480 (EDNS/IPv4),
>  1220 (EDNS/IPv6), or the advertized EDNS buffer size if that is
>  smaller than the EDNS default.
> 
>  The feature is enabled by default. You can disable it by configuring
>  NSD with --disable-minimal-responses.

Matthijs, 

Thanks for the 3.2.9 release. It looks like there are allot of good fixes in the release.

I'm trying to get a more thorough understanding of the mininal-responses feature in order to do a risk assessment of enabling it in our build.

I've done some archeology and from what I can tell, commits 3471 through 3473 are the total change. I could not find a bug referring to these commits.

Looking at the commits, I find this additional documentation in doc/REQUIREMENTS:
+  The feature 'minimize responses' is included since NSD 3.2.9.
+  NS RRsets that would go into the Authority section in positive
+  responses are not considered REQUIRED and therefore will NOT lead
+  to setting of the TC bit. 

As I see it, my biggest risk of taking this feature is that I could possibly cause unexpected behavior in any client expecting this information, even though the spec says it's optional.

Are there any other issues I should consider?

Thanks,
Todd