[arin-ppml] 2008-3 Support

[michael.dillon at bt.com]

> > But since IPv6 is
> > designed to make renumbering much simpler than on IPv4, 
> this does not 
> > seem like enough hardship to deserve a special policy.
> 
> What exactly is there in practical utilization of IPv6 that 
> makes it easier to renumber for a networking professional 
> managing more than a single router than IPv4?

To start with there is RFC 2894, i.e. router renumbering
functionality built into the IPv6 protocol suite. More
recently there is RFC 4192 "Procedures for Renumbering an 
IPv6 Network without a Flag Day".

For more info you might want to read "Preparing network 
configurations for IPv6 renumbering" which is available to
download free at
<http://inl.info.ucl.ac.be/publications/preparing-network-configurations
-ipv6-renumbering>

It may not be trivial or automatic but it is simpler.
Things like /48 per site make it easier to switch
providers since you only have to change the prefix,
not the lower bits of deployed addresses. IPv6 expects
hosts to have multiple addresses per interface so there
is no problem in assigning the new ISP's addresses 
to your devices BEFORE you connect to the new ISP.
And you don't have to remove the old ISP's addresses
until after you have disconnected from them.

Even so, it is clearly hard to renumber IPv4 networks and we don't
have special policies for community networks so that they can 
escape from this hardship.

--Michael Dillon