short ttl and servermmirroring

[Barry Margolin]

In article <XFMail.000210161455.tris at proteusweb.com>,
Tristan Aston  <tris at proteusweb.com> wrote:
>does anyone have any thoughts on using a very short ttl
>as part of a server mirroring plan ?
>
>I need a system in place that will enable me to,
>at a moments notice change what machine a domain
>points to.

The TTL isn't the only issue.  You also need to ensure that the slaves
update quickly.  You might have a 10-second TTL, but if you have a 1-hour
Refresh then the slaves may continue giving out old data for an hour.

If you use BIND 8 on the master and slaves this shouldn't be a problem, as
they support the NOTIFY protocol to initiate zone transfers quickly.

>Has anyone tried this ? Is it a common solution ?

It's done by Distributed Director and similar systems.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, 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.