Discussion on:

Managing DNS records in BIND on Linux

Zone files are not records. Zone files contain records. They are the raw storage format for the database.

The refresh, expire, and retry timeouts are used only by secondary servers for a domain, to decide when to get a fresh backup copy of the domain from the master server.

The "default TTL" entry in the SOA record no longer performs that function. It now is the "minimum TTL", and represents the time that clients should remember a negative answer (ie. an answer that the queried record does not exist).

The reverse zone file lacks a NS record. There must be at least one NS record for a domain. (Two nameservers per domain are preferable, for redundancy, and it's even better if they're on different subnets, in case of a router failure.)

The "@" syntax is a bit confusing for newcomers, and I avoid it in my domain files in favor of FQDN's. It can be useful in large systems where one uses template zone files to represent many domains.

Correcting my correction:

The "minimum TTL" is now the "negative TTL".

Someone please correct me if I'm wrong... I thought the reverse lookup file containing records was supposed to look more like this:(and minimum TTL is still acceptable/used in older systems. ie.. it still works with version of O/S it's running on ifthe BIND version hasn't been updated.)

@ IN SOA ns1.sample.com. (
200101111 ;serial
14400 ;refresh after 4 hours 3600 ;retry after 1 hour
604800 ;expire after 1 week
86400 ) ;minimum TTL of 1 day
;
71.219.204.212.in-addr.arpa. IN PTR www.sample.com.

Note that the SOA is just another record. You need one in every zone, but it's only the first in the file by convention, not by necessity. There's no special order to the records in the file.

A minimum file needs an SOA and an NS record. A domaincan contain any combination of other records.

hi
i installed bind9 with redhat 7.2 and now i have 4 named running when i use ps -ef and no named.pidm. where did i go wrong? thanks.
michael

I started using Webmin (www.webmin.com/webmin)
for administering my BIND8 (soon to be BIND9) installation.
As far as I can tell, this works out pretty good.
Easy adding of master/slave zones, easy adding of records, automatic update of the reverse zone and so on.

Anyone else using Webmin for this?
Anyone ever seen any weird effects?
I heard rumors that the Webmin Sendmail module is using old rules and can result in bad configurations, maybe better now.

Other than that, good article.
Foz