TTL Issues

[Chip Old]

On Fri, 6 Apr 2001, Ryan Crouch wrote:

> I recently installed 8.2.3-REL.
> Deleted all our zone files for the secondary DNS server. When the
> zone's are transferred over, the TTL value now exists on every line,
> much like the Bind4 zone files. The primary nameserver has the BIND 8
> compatible zonefiles, with the $TTL value set at the top, outside of
> the SOA. The secondary DNS files dont have the $TTL at the top, after
> the zone transfer has occurred.

That's normal.  In your master zone file the "$TTL xxxx" value above the
SOA record is the default TTL value.  When the master loads the zone, that
default is assigned to every record that does not have its own explicit
TTL.  If you do ndc dumpdb, then scan through named_dump.db looking for
records from that zone, you'll see that each record includes the TTL.
When a slave transfers the zone, it's getting the zone as it exists
in the master's memory, not from the zone file itself.  That memory image
includes the TTL value, which is why your zone files on the slave include
the TTL in each record but not the $TTL xxxx line from the master zone
file.

-- 
Chip Old (Francis E. Old)               E-Mail:  fold at bcpl.net
Manager, BCPL Network Services          Voice:   410-887-6180
Manager, BCPL.NET Internet Services     FAX:     410-887-2091
320 York Road
Towson, Maryland 21204 U.S.A.