Renumbering with IPv6 WAS: [ppml] Get you IPv6 Today,

Phil Howard phil-arin-ppml at
Thu Jan 9 17:36:34 EST 2003

On Thu, Jan 09, 2003 at 02:12:57AM -0600, Mury wrote:

| > But the point is, you still have to syncronize the event of switching
| > routers and switching the DNS data, if you don't have the opportunity
| > to overlap.
| I don't think I understand what you are saying.  We switch routers and DNS
| data every day.  It's rarely a problem if you know ahead of time.

Sometimes you don't know ahead of time.  And sometimes even if you do,
you have to "throw the switch" when the registrar/registry does, and you
don't really have control over that, or even information about it.

I also see the quality of registrar operations sliding downhill, and
being able to NOT make delegated NS changes is a major plus to me.
I've had trouble putting my changes through a few times (for example
Network Solutions' host object updates I believe test the wrong field
for the NS hostname authority).  And I've had customers completely
unreachable when changes happen.  It's something I'd rather not have
to ever change.

| > And if an ISP goes bankrupt without notice (yes, it happens) and you
| > suddenly have to switch to another, how do you restore your DNS IPs
| > when you can't get any verification because your GTLD A records still
| > point to the old ones?
| Of course ISPs go bankrupt.  They usually keep operating however.  Even
| so, if they were to shut their doors completely it would be awesome to be
| able to simply change a couple lines in a router and in a DNS server than
| the total nightmare you can have with having to renumber with IPv4.

Well, certainly the renumbering can be an issue.  But if the numbers
come from a defunct ISP, you can NAT the network all at once and not
have to worry that the addresses you have internally can't reach anyone
because those are the numbers of a defunct ISP.  I've had two customers
we quickly renumbered that way, by using NAT and just mapping all the
old IPs to new IPs, or to a single new IP.  They _may_ even still be
using those old non-private addresses internally for all I know.

My concern is reachability of my primary delegated NS server, which has
to be identified by the appropriate address record at the GTLD or other
TLD server.  IPv6 can be an advantage in that respect if the address is
permanent (in the sense that I don't have to change it while still in
business).  I'm not talking about recoverable assets in a bankruptcy;
I'm talking about planning to ensure 5 9's reachability.  And one of
those things does involve not having to change outside views of the
address space.

I had believed IPv6 would offer me these things.  Eventually I determined
that does not appear to be the case.  Scaling routing remains a serious
issue, and is holding back universal portability.  I see potential solutions
but I don't knwo of those people who are in the midst of actually making
such technological decisions are even working in that direction or not.

| Phil Howard - KA9WGN |   Dallas   | |
| phil-nospam at | Texas, USA |    |

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