Primary Reloading and Secondary Zones Expiring
pgoode at cohesive.com
Tue Nov 16 18:52:36 UTC 1999
I'm a little confused about secondary zone expiration and am looking for
I have 2 primary DNS servers running BIND 8.2.1 (for load balancing and
redundancy) and a secondary DNS server running BIND 8.1.2. These servers
are SOA for thousands of domains. By default I'm letting DNS Notify handle
the new/modified zones and their transfers to the secondary.
I was recently checking the secondary server to make sure that new zones
were getting transfered. I read in "DNS and BIND" that DNS notify generally
causes the zone transfers to happen within 15 minutes. Some of the new
zones were taking 3 and 4 days to transfer to the secondary. I then turned
on debugging level 1 on the secondary server and found what looked like the
server being overloaded with zone maintenance, ie., expiring and tranfering
After discovering this I changed all zone files from a 24 hour EXPIRE to 7
days, and a 4 hour TTL to 24 hours. I then ran a script on the secondary
server to manually run named-xfer against all zones and used the serial
number of 0 to force transfers, after which I rebooted the secondary server
to give it a "fresh" start. I expected to see the zone maintenance
decrease greatly and new zones added to notify and transfer in a more
reasonable amount of time. What I see now is that some of those new zones
are still taking days to transfer to the secondary and more zone maintenance
than I would have expected.
The only thing that I can see that may affect the way all of the zones are
being handled is that the primary server gets reloaded on a regular interval
to rebuild named.conf and propogate the new/modified/deleted information to
the other primary server. We also reload the secondary on a regular
interval to pick up the changes made to named.conf. These reloads happen
because there are zone additions/modifications/deletions every day.
This all leads me to some questions:
1. If we reload the primary server does that cause the primary to notify the
secondary to transfer zones?
2. If we reload the secondary server does that somehow cause the secondary
zones to expire and need to be transfered?
3. Is there a better way of handling all of the
additions/modifications/deletions that occur on a daily basis?
Thanks in advancefor any help and/or suggestions.
Exodus Professional Services
peter.goode at exodus.net
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