Question about 8.2.2 $TTL

Barry Margolin barmar at bbnplanet.com
Thu Nov 11 15:33:26 UTC 1999


In article <199911111419.IAA11068 at achilles.ctd.anl.gov>,
Barry Finkel  <b19141 at achilles.ctd.anl.gov> wrote:
>I have a question regarding the 8.2.2 $TTL statement.  I am currently
>running 8.1.2, and I want to upgrade to 8.2.2 for testing with the
>Microsoft Windows 2000 DNS.  If I want to upgrade my primary DNS, I
>need to put $TTL directives in all of my primary zones.  Will the $TTL
>be transfered with the zones to my secondaries.  forcing me to have to
>upgrade my secondaries to 8.2.2 at the same time?  Thanks.

Did you bother reading RFC 2308?  It's quite clear on this:

   The second, the default TTL of RRs which contain no explicit TTL in
   the master zone file, is relevant only at the primary server.  After
   a zone transfer all RRs have explicit TTLs and it is impossible to
   determine whether the TTL for a record was explicitly set or derived
   from the default after a zone transfer.  Where a server does not
   require RRs to include the TTL value explicitly, it should provide a
   mechanism, not being the value of the MINIMUM field of the SOA
   record, from which the missing TTL values are obtained.  How this is
   done is implementation dependent.

In the case of BIND 8.2, the implementation dependent mechanism is the $TTL
directive.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.


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