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DNS bind - use of /etc/named directory

Hello,

For many years we have modified the '/etc/named.conf' file to include local
settings. The disadvantage with this is of course that when bind is updated, it
creates an '/etc/named.conf.rpmnew' file. We then have to determine what is
new, and apply the relevant changes to our modified named.conf file.

There is, however, an '/etc/named' directory which I assumed was for local
configuration settings. The main '/etc/named.conf' file makes no mention of
this directory, so (I suspect) any config files in '/etc/named' would, by
default, just be ignored.

As far as I can tell we could put our local configuration settings into a file
in '/etc/named', but we would then, once again, have to modify
'/etc/named.conf' to tell it to include config files in '/etc/named'. We would
then be back at square one in that any bind update would create an 'rpmnew'
file.

I admit I haven't actually tested this, but has anyone used the '/etc/named'
directory and not had to modify the main '/etc/named.conf' file?

I suspect, if not, then this should be raised as a possible bug since it would
make sense not to have to modify the main configuration file at all.

Thanks,

John.

Comments

Re: DNS bind - use of /etc/named directory

By John Horne at 12/07/2018 - 11:39

On Tue, 2018-12-04 at 00:51 +0000, John Horne wrote:
Upon starting bind/named though it complained with
"/etc/named/local_named.conf:2: 'options' redefined near 'options'"
because I had defined the 'options' section in my new config file, as well as
it being present in the supplied default '/etc/named.conf'.

So, in order to add extra options settings, I see no way other than modifying
the supplied '/etc/named.conf' file.

Note: it may well be possible to 'include' a file within the '/etc/named.conf'
options section, provided that file only contained 'options' settings. In our
case we also want to modify the logging section slightly, so we would need
another include in the 'logging' section. Overall, we would end up modifying
the '/etc/named.conf' file with include files just as much as if we just added
the new options directly to it. Trying to use '/etc/named' in our case is just
not worth it.

John.

Re: DNS bind - use of /etc/named directory

By Johnny Hughes v... at 12/04/2018 - 04:19

The '/etc/named.conf.rpmnew' file supplied is a bare minimum to
"configure the ... server as a caching only nameserver (as a localhost
DNS resolver only)". As soon as you start adding any structure to it
things change, not just are added to. See
'/usr/share/doc/bind-*/sample/etc/named.conf' for example. Probably the
biggest "gotcha" is that as soon as you use _any_ views you MUST use
views for _all_ zones.

If you were to move the default '/etc/named.conf.rpmnew' to
'/etc/named.conf' and add an 'include "/etc/named/*";', line as you
suggest, you would be building problems for the future. Let's say you
dropped in 'internal.conf' which had a simple 'view "internal" stanza -
then your root hints, localhost, localhost IPV6 and reverse localhosts
would disappear. Just what you wouldn't want at 00:51 !

What you can do safely is to include the zone definitions in a separate
file (see '/etc/named.rfc1912.zones' for example) and include that file.
Doing things this way means that your main configuration file can be
written to either use views or not, and to just include your zone
definitions in the appropriate place. See the sample file for an example.

HTH,

Martin

On 04/12/18 00:51, John Horne wrote:

Re: DNS bind - use of /etc/named directory

By John Horne at 12/04/2018 - 05:41

On Tue, 2018-12-04 at 08:19 +0000, J Martin Rushton via CentOS wrote:
However, we don't use views and the local settings are not for zones. We do
currently have a separate zone file, but again that requires an 'include' in
the main '/etc/named.conf'. If a local settings file (in '/etc/named') could be
used, then we would simply 'include' the zone file in that. Ultimately, the
main named.conf file would remain untouched.

John.

Re: DNS bind - use of /etc/named directory

By Johnny Hughes v... at 12/04/2018 - 06:08

On 04/12/18 09:41, John Horne wrote:
Regards,
Martin