zone file settings question

[Adam Tkac]

On Mon, Oct 15, 2007 at 01:33:29PM -0400, Madison Kelly wrote:
> Hi all,
> 
>    I was trying to find out what certain settings effect. For example, 
> in a zone file with the following...
> 
> -=-=-=-=-
> $ORIGIN .
> $TTL 38400	; 10 hours 40 minutes
> domain.com		IN SOA	ns1.nsserver.com. admin.domain.com. (
> 				2007101501 ; serial
> 				10800      ; refresh (3 hours)
> 				3600       ; retry (1 hour)
> 				86400      ; expire (1 day)
> 				38400      ; minimum (10 hours 40 minutes)
> 				)
> ...
> -=-=-=-=-
> 
>    What do these fields mean?
> 
> - refresh
> Would I be right in guessing that this time is how often a client would 
> try to check the zone for updates, but failing to get a response would 
> keep using the TTL so long as it was valid?

Means how often secondary nameservers transfer zone from primary

> 
> - retry
> Is this the amount of time, after a failed attempt to contact the 
> server, that a client would wait before trying again?

If zone transfer isn't successfull this specify how often will secondary retry transfer

> 
> - expire
> How is this different from 'ttl'?

When secondary server can't get zone from primary after this time secondary server stops returning authoritative responses for domain

> 
> - minimum
> Not sure even of a guess...

I think currently means negative TTL - how long will be cached that resource record doesn't exist

Adam