Manual & dynamic update-maintenance of zone files

[Barry Finkel]

"Umakanth V.S" <uvs at cdotb.ernet.in> wrote:

> A range of IP addressess for dynamic assignment is properly defined in
> the DHCP server config file. Named (primary)  & dhcpd are both running
> the same box with a static IP address.
> 
> I will just clarify the issue that I have raised. I have a setup of
> around 500 systems. Most of the systems will be assigned IP addreses
> via DHCP, but I have to manually assign static addresses to a few
> systems (on  as required basis). There is absolutely no problem in the
> updation of the DNS database files (A and PTR records) by DDNS for
> those systems that have been assigned dynamic addresses. For the
> systems that I am statically assigning an address, I will have to
> manually update the DNS database files and manually increment the
> serial number (which is automatic in the case of DHCP assigned
> addreses) so that the updates are sent to the DNS secondary servers.
> When the serial number is manually incremented and named is restarted,
> it exits because the serial number in the database files on disk and in
> the journal files are not in sync. ( In any case, the BIND
> documentation specifically prohibits manual modification of the DNS
> database files when updates thru DDNS are being done). The question is
> how to resolve this issue.
> 
> Any help will be appreciated.

You said the "magic words" - "the BIND documentation specifically 
prohibits manual modification of the DNS database files when updates 
thru DDNS are being done."  If you have a zone that is subject to
DDNS, BIND will apply the dynamic updates to the zone copy in memory.
It will also write a log file so that the update can be re-done if the
server crashes.  Eventually, BIND will write the updated zone to
disk.  And that new disk file will NOT have all of the contents of the
original manually-created zone.  All comments will be missing, and
the order of the records in the file will appear to be random.

You have no idea when BIND will decide to write an update to the disk
file, so if you have updated the disk file manually, BIND will
overwrite your manual updates.  All subsequent manual updates to the
zone must be done via the nsupdate utility supplied with BIND.
----------------------------------------------------------------------
Barry S. Finkel
Electronics and Computing Technologies Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
9700 South Cass Avenue               Facsimile:+1 (630) 252-9689
Building 221, Room B236              Internet: BSFinkel at anl.gov
Argonne, IL   60439-4844             IBMMAIL:  I1004994