Regarding allow-update:

- We do try to avoid ‘breaking existing deployments’ with this sort of change. 
We do also have to balance maintaining existing deployments with making 
improvements in security and usability. 

- When we ‘clarified’ behavior of BIND in 9.13.5 preventing the use of 
allow-update as an inherited option, apparently it was not entirely clear from 
code examination what the current behavior was.  Therefore, we made a more 
invasive change than we would normally make on purpose, without a fair amount 
of public notice, and possibly even some sort of open poll.

- We had no idea how common a configuration leveraging the inherited 
allow-update might be among users that we have no direct support relationship 
with. We have heard from several of you that this is an important feature for 
you:  I think we were surprised at this. Thank you for the feedback. This is 
the purpose of having development releases, so that early adopters can try 
upcoming changes and give us feedback. 

- We have decided to treat this change as a regression bug, and to fix it in 
9.14.1.  Alan argued that we should hold 9.14.0 and fix it there: however we 
have decided to go ahead with 9.14.0 with the change we already made in 
allow-update, which we will highlight in the release notes as a ‘known issue'.  
People who rely on a global-allow-update will simply have to wait for 9.14.1 
where we will attempt to restore the prior behavior.   This is not a ’neat’ 
resolution, as it violates our normal policy of not changing configuration 
defaults in the middle of a stable branch, but it should be an adequate 
solution. 

- Reasonable people (some of my colleagues at ISC) feel that users may 
’self-foot-shoot’ with an inherited allow-update, and that the inherited 
behavior may not be obvious (similar options such as update-policy are not 
inherited). At ISC we hear not infrequently from people who have inherited a 
BIND implementation after the original administrator left, and they are 
maintaining a configuration they don’t understand. This experience, coupled 
with a generally increasing concern about DNS security makes a reasonable 
argument for limiting opportunities to ‘accidentally’ allow updates when adding 
new zones. 

We may still implement this or a similar change in the future, but only after 
more discussion and communication and advance warning.  We have noted the 
suggestions for some sort of zone templating, and for a log of the full zone 
configuration, reflecting inherited options as well as explicitly configured 
options. 

Regards,

Vicky Risk
Product Manager for BIND


_______________________________________________
Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe 
from this list

bind-users mailing list
bind-users@lists.isc.org
https://lists.isc.org/mailman/listinfo/bind-users

Reply via email to