Changing $TTL for many zones

[chuck yerkes]

....
>>>Would this work?
>>>   
>>>
>>
>>Yes. But why ? You still have to edit at least the SOA record to increase 
>>serial nr.
>>
> 
> Exactly. I would go further and suggest that, since the SOA needs to be 
> changed anyway, just give an explicit TTL to the SOA RR, and thus 
> dispense with the $TTL directive completely (my assumption here is that 
> the SOA RR is the first RR in the zone file).

Sanity would suggest GENERATING part of your zones anyway.

I host a couple hundred zones.  Frankly, for a lot of them,
the "file" is one of 4 (variations of www and mail between
a couple machines).

But I'm leaning towards keeping the SOA in one file, the zone
content in another and using m4 to create the actual zone file
drawing from those.

If the generic m4 template that draws them in defines the $TTL
and certain SOA values (pretty much all but serial number), then
great.

combine with "make" and it's a lot easier.  if you really need
to update a bunch of zones, you touch the "$ZONENAME.data" file
and run "make"