Re: Using IPv6 with prefixes shorter than a /64 on a LAN

[Owen DeLong <owen () delong com>]

On Feb 1, 2011, at 7:43 AM, Jack Bates wrote:

> On 2/1/2011 9:23 AM, Tim Franklin wrote:
> > I really,*really*  expect my CPE router*not*  to remove global
> > addresses from the LAN interface(s) when the link to the Internet
> > goes down.  My internal services should go on working with their
> > global addresses.  This is how my tunneled IPv6 works today.
> >
> > Am I being an unreasonable engineer in this respect?
>
> This depends. Will you have a static assignment? What will be the lifetime values issued by your ISP? Granted, You 
> should be able to maintain them at least 2 hours, though in a multiple router scenario, I'm not sure how well they'll 
> take to routing unpreferred prefixes.
>
> ULA isn't a bad thing. It also doesn't interfere with your GUA. There's really no reason NOT to have ULA in CPE 
> devices. If your DSL is down for a day or two, do you really want to worry about addressing? Do you want to connect 
> to the Internet before you can have addressing?
ULA is a bad thing. There are multiple problems likely to be caused by it.

There really are reasons NOT to put ULA in CPE devices. There are better solutions
to the downed internet connection than ULA.


Owen

> Jack