>You're making lots of assumptions.
>
>
>1) That client DNS systems will actually honor such a TTL. Many
> don't (claim they're broken all you want, but these are the facts).
>
>2) That client SOFTWARE will actually go back and ask again for the
> IP number. Several won't (Netscrape being rumored to be one of
> them). TTLs are irrelavent in that case.
>
>Go ahead and try to tell your customer, who purchased web service from you,
>that you have the right to disrupt their operations at any time and under
>any pretense and see how many of them you have left.I would hope that your contract didn't state the customer was guaranteed the
same IP for eternity; if so, your legal department needs to be hanged. You
can either renumber once into an RFC 1918 block and use NAT, or you can
renumber into a new space every time you change providers. Your customers
will understand renumbering once, especially if you can find a way to
improve services with it. They'll look elsewhere if it happens more than
once or twice, or if they get nothing from it.
Tell you what.
You get ALL the providers to agree via BCP that all customers must run NAT
on their leased line connections.
Every one of them.
That is, a nice level playing field.
Then come back here and let's talk.
Or is this a "big guys don't have to" thing again? Because if it is, then
you're right back where you started.