So Don, You're saying that Xtra and Telstra (and others) deliberately go out of their way to engineer their DNS servers to _ignore_ the TTL variable and instead make up their own? Interested to hear how you come to that conclusion? '48 hours' is fine if you're explaining to a newb and you know for certain that the TTL involved is less than that. I once came across a customer whos previous host, in a fit of vengance, upped their TTL to 4 weeks just before the domain was transferred... It is very easy for someone to look up the legacy record, find the TTL variable and give the customer a realistic expectation that their domain will have reduction in service over the transition period (duration of TTL) which will gradually resolve itself as ISPs clear their caches and pull new data. Its also not hard for customer service reps to provide advice to customers - like 'when you know you're going to be making a change, have the record in question (or the entire zone) have a reduced TTL - say, 15 minutes - configured. (This will usually require translation, but again, explaining to people that its a step that'll minimise their downtime, is usually sufficient, whether or not technical reasoning is provided.) I further seem to recall suggesting to people who were moving their domains away, to get back in touch with their old host after a couple of days to ensure that any legacy zones _had_ been purged (and not overlooked). Puts the onus back on the customer. 5 minutes on the phone could save a hellovalot of heartache later, when you discover that your email is 'missing, presumed bounced'. Mark. On Fri, 27 Oct 2006, Don Gould wrote:
I think this is a fantastic idea...
...though I hate to rain on your parade...
I've found the ISPs seem to ignore the ttl which makes reducing it pointless.
I just tell clients that it WILL be down for up to 48 hours and anything less is the good karma you've earned in the universe.
It would be helpful if ISPs like Xtra and Telstra (and others) didn't set up their DNS servers to ignore shorter ttl.
I've also found that domains will go live from overseas before they come live here in NZ when in the .co.nz space.
Anyone who can improve things gets my vote for PM! :) Most appreciated :) </rant>
Cheers Don
Simon Lyall wrote:
After a few recent instances I am getting sick of companies who transfer their DNS/Servers from one provider to another and then wonder why the old data is still cached by 3rd parties for 24 hours (or whatever).
How do people feel about a "best practice" document on this that we could encourage people to follow ( perhaps the DNC could publish) for people moving their domain between providers. Just the basics like, dropping the TTLs, getting all the servers data in the right order etc?
Similar to this:
http://www.onr.com/services/data_center/colocation/transfer_tips.html
Thoguhts?
-- Don Gould www.thinkdesignprint.co.nz - www.tcn.bowenvale.co.nz - www.bowenvale.co.nz - www.hearingbooks.co.nz - www.buxtonsquare.co.nz - SkypeMe: ThinkDesignPrint - Good ideas: www.solarking.co.nz
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