Q: Switching connectivity providers and root name server updates

[Barry Margolin]

In article <9o5eeb$efg at pub3.rc.vix.com>,
Chin Fang  <fangchin at Stanford.EDU> wrote:
>
>Barry,
>
>Many thanks for your insight.
>
>> 
>> Even when the GTLD servers pick up the A record change, you still have the
>> problem that the TTL on those glue records is 2 days.  So does it really
>> make a big difference whether they pick up the change from NSI in 1 hour or
>> 6 hours?  That changes the actual worst-case timeout from 49 hours to 54
>> hours?
>
>In that case, how do you see the following as a compromise?
>
>  Instead asking our registrar to enter the IP addresses of our name
>  servers in the Registry database a couple hours ahead our swing-over
>  hour, we can ask our registrar to enter the new IP address info at the
>  first NSI daily update (i.e. 1000 GMT or 3:00 AM PDT).  This way, the
>  effect from the root server glue record TTL is shortened by 10 hours.

Trying to time the registry changes is futile, IMHO.  Any change you make
via a registrar should be thought of as slowly propagating over a period of
at least 2 days, because of the different delays in getting to each GTLD
server (at T1 speed it takes several hours for the compressed COM zone to
be transferred) and the caching that all the rest of the nameservers in the
world do.

>  If that's not enough, we can even ask our registrar to enter the new
>  IP addresses into the Registry database one day ahead.
>
>I understand doing so will cause intermittent access problems to our
>site to some parties.

Not if your off-site secondary servers are still available during that
time.  As long as the GTLD servers always have at least one working
nameserver listed, you should be OK.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
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