Reachability (IP vs. DNS) was Re: ARIN Proposal

>>... any of us who have been through one or more area code renumbering
>>instances knows this is not true. It can happen, it does happen, just the
>>Internet has smaller prefixes. Forced by at outside organization to change
>>with no recourse or cost recovery. It just so happens that the people
>>making the decisions are almost always an arm of the state government.
>
At 10:24 PM -0700 1/22/97, Stephen Satchell wrote, responding in part to
the above, which was at a sufficient level of quoting that I am no longer
sure who wrote it,

>There is another flaw in this analogy:  there is an announcement, a
>parallel-operation period where *both* Area Codes are valid, then the final
>cut-over.  I've been through this a couple of times with Chicago, New
>England, and Bay Area clients.  (I'm also facing this with the idea to
>split Nevada into two area codes -- I'm in Northern Nevada and Clark County
>[Las Vegas/Henderson] run the state, so my area code is sure to change.)
>
>With IP numbers, you don't have any of those options, as I've mentioned in
>what should have been a prior rock.

This isn't a criticism of Mr. Satchell; I am just trying to continue a
thread where the quoting has gotten very confusing (to me at least).  Let's
try to avoid making every technical problem an IP problem that requires an
IP solution.

>From a user perspective and what IMHO should be a business perspective, the
issue is whether a given node is reachable or not.  As long as my browser
can find www.foo.com, I have solved my problem.

www.foo.com is not, as people will notice, an IP address.  It is a DNS name.

In the PIER working group and elsewhere, there is a technical consensus
that network endpoints -- certainly servers and to a lesser extent clients
-- should be referred to by DNS name, not IP address.

[Yes, I know DNS is not perfect, and there are cache timeouts, etc., to
consider.  Nevertheless...]  Making extensive use of naming rather than
addressing, in many respects, finesses a very large part of address
portability issue.  DNS has the capability of hiding the actual address
from end users.

DNS is best as a server solution.  For client addressing, schemes such as
DHCP and IPCP dynamic assignment will reduce the workload in renumbering.
Do remember any of these dynamic schemes can give a semi-random address, or
a fixed address based on some identifier such as MAC address.    The key
issue in making renumbering less painful is to minimize the number of
places where renumbering has to be done (e.g., address assignment servers
rather then every PC), not som much reducing the absolute numbers of
addresses assigned.

Yes, I know there are operational problems with fully dynamic addressing,
where it is unpredictable what address one gets at a given time, and thus
ping/traceroute/SNMP gets...interesting.  There are ways of dealing with
this today, ranging from manual procedures to proprietary servers for right
now, the the Dynamic DNS Update work going on in the IETF.  IPv6,
incidentally, has a significant number of capabilities to simplify
renumbering, although IPv6 does not help the routing table size problem.

Yes, in a provider change in a provider-based addressing scheme, some
hard-coded IP addresses will need to change.  But good practices can
minimize that.

Nothing is perfect.