Implementations/suggestions for Multihoming IPv6 for DSL sites

Owen DeLong owen at
Fri Apr 8 16:20:22 UTC 2011

On Apr 8, 2011, at 6:54 AM, Joe Maimon wrote:

> Owen DeLong wrote:
>> On Apr 7, 2011, at 8:13 PM, Tom Limoncelli wrote:
>>> On Thu, Apr 7, 2011 at 10:51 PM, Owen DeLong<owen at>  wrote:
>>>> There is no need for NAT in order to multiple-home. BGP is every bit as effective and much simpler.
>>> I know a lot of small businesses with one FiOS link and one Comcast
>>> link and I don't think they're going to be able to do BGP. Their
>>> providers won't do it and their prem equipment doesn't support it and
>>> the local IT person doesn't have the know-how to do it.  I know that
>>> the typical NANOG member isn't in this category, but this is a
>>> use-case that is very common and outnumbers NANOG members.
>> I have one DSL and one Cable. Neither the DSL provider nor Comcast
>> will do BGP. I do BGP just fine without them doing BGP.
>> Owen
> Your use case requires at minimum a triangle, ideally a rectangle.
I'm not sure what you mean by traingle/rectangle other than the same
thing that would be required for any actual multi-homing scenario.

> Along for the ride comes encapsulation, overhead, additional bottlenecks and failure scenarios. The payoff has to be worth it and that usually means something more than the elimination of napt on outbound internet access, such as inbound access to bring-your-own-ip.
The encapsulation and overhead is small. In general, all of the failures experienced to date have been the
result of the underlying DSL or Cable provider.

I guess the value of eliminating the damage caused by NAT/NAPT/PAT/whatever you want to call the
abysmal hack so many people choose to live with because they perceive a lack of options is a value
each organization has to determine in their environment. In my environment, this is a very low
overhead and very low cost way to solve the issue and get reliable multihoming with portable
accessible addresses and avoid having to involve silly third parties in things like making a VNC
connection back to one of my hosts from the road.

> For anyone to do this requires beyond basic know-how and a willing 3rd point. I'll do it for a customer, but it is by no means readily available, or even ideal, so lets stop hyping it.
We can agree to disagree. I think it is readily available and I think it is a significantly better solution
than NAT. Ideal? no. Ideal would be when access providers start offering cost-effective services that
include dynamic routing. However, until that happens, this is the next best thing.


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