Reg: TTL & Refresh

[Barry Margolin]

In article <bj9a5e$18lp$1 at sf1.isc.org>, Durai <tech_durai at lycos.co.uk> wrote:
>Hi All,
>I am new to DNS.

Then you should get the book "DNS & BIND" by Albitz & Liu.  It explains
just about everything.

>I am having file with like following content:
>
>@   IN  SOA     nameserver.place.dom.  postmaster.place.dom. (
>                               1            ; serial number
>                               3600         ; refresh   [1h]
>                               600          ; retry     [10m]
>                               86400        ; expire    [1d]
>                               3600 )       ; min TTL   [1h]
>
>My doubt is, I am having the zone files as master. When the TTL time &
>refresh expires, What will happen?

The TTL controls caching nameservers.  When it expires, the server discards
the record, and the next time a client tries to look that name up the
server queries one of the authoritative servers.

Refresh controls slave nameservers.  When it expires, the slave asks the
master for the serial number.  If it has increased, the slave performs a
zone transfer to get a new copy of the zone.

-- 
Barry Margolin, barry.margolin at level3.com
Level(3), Woburn, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.