Question about migrating to IPv6 with multiple upstreams.

Owen DeLong owen at
Tue Jun 14 21:46:04 UTC 2011

On Jun 14, 2011, at 10:52 AM, Ray Soucy wrote:

> It's a security and operational issue.
> The perception is that it's easier to monitor, manage, and filter one
> address per host instead of 3.  For most in the enterprise world it's
> a non-starter to have that setup; even if that perception is a false
> one.

Yes... The key word there is perception. The question is whether it makes
more sense to put effort into correcting mis-perceptions or to put the effort
into providing workarounds which provide a sub-par networking experience
to the end user.

IMNSHO, it is better to put effort into education. I'm surprised to find someone
from a .EDU on the opposite side of that thought. One would normally expect
them to favor the idea of education over hackery.

> Not sure I have the energy to re-hash the tired old NAT debate though. ;-)

That sound you hear is me breathing a sigh of relief. I will continue to do
it as long as it remains necessary, but, I'm tired of it too.


> On Tue, Jun 14, 2011 at 1:38 PM,  <Valdis.Kletnieks at> wrote:
>> On Tue, 14 Jun 2011 13:04:11 EDT, Ray Soucy said:
>>> A better solution; and the one I think that will be adopted in the
>>> long term as soon as vendors come into the fold, is to swap out
>>> RFC1918 with ULA addressing, and swap out PAT with NPT; then use
>>> policy routing to handle load balancing and failover the way most
>>> "dual WAN" multifunction firewalls do today.
>>> Example:
>>> Each provider provides a 48-bit prefix;
>>> Internally you use a ULA prefix; and setup prefix translation so that
>>> the prefix gets swapped appropriately for each uplink interface.  This
>>> provides the benefits of "NAT" used today; without the drawback of
>>> having to do funky port rewriting and restricting incoming traffic to
>>> mapped assignments or UPnP.
>> Why do people insist on creating solutions where each host has exactly one IPv6
>> address, instead of letting each host have *three* (in this case) - a ULA and
>> two provider-prefixed addresses?
> -- 
> Ray Soucy
> Epic Communications Specialist
> Phone: +1 (207) 561-3526
> Networkmaine, a Unit of the University of Maine System

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