Q: Switching connectivity providers and root name server updates

[Chin Fang]

We plan to switch to a different connectivity provider, and thus we will
have to swith our IP block as well.

To minimize downtime, we will do the following:

o lower our TTL one week ahead
o ask our registrar to update the IP addresses of our name servers
  in the Registry database a couple hours ahead of our switch over hour
  (see below)
o do the swith over at 3:00 PM PDT

The reason why we want to do the switch-over at 3:00PM (i.e. 2200 GMT)
is because as far as we know, it's the hour at which Network
Solutions, Inc. (NSI) carries out its 2nd daily root name server zone
file transfer.

Although we believe the above is a reasonable approach, we are still
not sure how much it can minimize our downtime.  

For instance, after the 2nd daily NSI daily root server zone file
transfer, how soon *all* root name servers for GTLD would pick up the
new IP address info of our name servers?  

We believe the lowered TTL should help in this regard, but if a lot
root servers do not timely (say within a hour or two) pick up the new
IP addresses of our name servers, our site will remain invisible to
many folks for quite a while.  This is the potential problem that we
don't know how to deal with yet.

Any suggestions or comments?

Thanks and regards,

Chin Fang
fangchin at leland.stanford.edu