nanog mailing list archives

Re: moving to IPv6


From: Pedro Marques <roque () cisco com>
Date: 03 Nov 1997 20:53:11 -0800

phil () charon milepost com (Phil Howard) writes:

 
The transition to IPv6 is clearly going to have some difficulties.  We are
waiting on:

1.  Network equipment, with translation

2.  End user software

3.  Address space assignment

nice list.

IPv6-only space is of less value than IPv4-private space until IPv6
becomes at least fully routeable over the Internet.  So the backbone
networks are going to have to take the lead to make it happen.  Even
when it is routeable, it has to work on all the ends, which will thus
have to have translations to make their IPv4 space appear as IPv6sub4
space.

The best workable scenario I can see so far is one where IOS and other
routing software includes translation between IPv4 and IPv6

IOS IPv6 prototype does include that facility. It translates to and from
an arbitrary v4 network and an arbitrary v6 network.

Something is thus needed to encourage customers to move into IPv6 even
when it is fully routeable.

That is really the key issue... because even with IPv6 NAT (protocol
translation) working, IPv6 is as actractive as using IPv4 NAT, unless
it brings some value added to the end customers... The potential
advantage i see is autoconfiguration support. But DHCP can actually
do the same job reasonably well.

But just having IOS translating IPv4 <-> IPv6s4 is not enough.

Agreed.

We will need to manage the new IPv6 network.  All the various tools we
use will need to understanding IPv6 and how it it configured on the
network.  Routing will have to work right even during the transition
to this, which means BGP4v6 has to be there capable of understanding
IPv6 space at some point in time.

BGP4 + Multiprotocol Extensions is able to do the job. And it is working
resonably well...


Routing issues will become different in IPv6.

How ?


If IPv6 allocations will have varying sizes like CIDR, then we might
continue to have issues of size based route filtering.  OTOH, with the
right methods of allocating IPv6 space, no one should ever have to come
back to get more space.  Eventually that should mean fewer routes as
IPv4/IPv6s4 closes down.  Route filtering should be encouraged on IPv4
space and prohibited on IPv6 space, at that point, IMHO.

I don't think i really understand your point here....

The only "difference" when it comes to routing information i can think off
is that in IPv6 there isn't suppose to be address ownership (which creates
holes into CIDR blocks)... but it seems to me that the same policy is
being adopted for IPv4.

  Pedro.


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