Details of Propagation

[Jeff Lasman]

Whizkid25468 wrote:

> I am, com, I meant to write com's servers (that was a, uhh, keyboard error,
> yeah, keyboard), but knowing about the root servers can't hurt /;-)<<. So
> when are com's servers supposed to be updated?

I, too, keep hearing 5am and 5pm, and I'm certainly no expert, but I
have seen that when I change a nameserver's IP# or add a nameserver at
some point in the afternoon (I'm in California, PDT, currently -0700),
it's usually in the TLD servers by the next morning.  So 5am/5pm is
definitely a possibility (as uncertain as that sounds).

> > > Finally, I've been *unreliably* informed that propagation time from the
> > > point of view of using your ISP's nameserver can depend on the size of
> your
> > > ISP, the type of nameserver you're on, and how often it's *set to
> update*.
> > > Isn't propagation (once the root servers update) purely dependant on the
> > > TTLs of the affected records? The size of the ISP shouldn't matter!
> >
> > True.
> 
> Oh good, my entire understanding of the DNS isn't completly off the mark
> then /:-)<<.

Again, I'm no expert, but it's been my experience (and I've heard from
others) that aol seems to ignore TTL and has their own agenda for
updating.  Some people add that they only do it if the TTL is
"unreasonably" short, but no one seems to know what "unreasonably" means
<frown>.

> Unless you use Dynamic DNS /:-\<<. A component of that is to turn the TTL
> down really low on your records, isn't it?

That depends on how badly you want your systems to be found <smile>.  In
general yes, but you shouldn't be using Dynamic DNS for systems visible
on the 'net, and for local DNS, it doesn't really matter.

And in case you haven't noticed, there's still a lot of mystery in what
is without a doubt the most important service on the Internet.

Jeff
-- 
Jeff Lasman, nobaloney.net, P. O. Box 52672, Riverside, CA  92517 US
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