> > Typical settings are 60 minutes or 6 hours.
> Isn't the normal setting 24 hours?
60 minutes do sound a low value for me, too. I remember that there are some
RIPE recommendations for minimum and maximum TTLs... but I do not know them.
Generally the longer the better (hmmm... I am talking about some serious
stuff here!:-)), some set it for 7 days or more in order to reduce DNS
traffic, but that often causes problems if you change your zone files - for
example if you change your MX records... resulting your mails going in ad
hoc directions :-)
You can find some comments on this issue on the web. For example combining
TTL settings with expiration (or whatever that field is called) can be used
to smoothly change your zone files basically all over the world at the same
time, if say, you are going through a big IP-change - but of course only if
your TTL settings are respected by other servers.
- Csongor
