Re: ULA scope [draft-ietf-6man-rfc3484-revise-05.txt]

[Brian E Carpenter <[e-mail]>]

On 2012-03-17 19:22, Dave Thaler wrote:
> Brian Carpenter writes:
> [...]
>> Let me be clear. If a local service has (for some reason) both a ULA and a non-
>> ULA global address, and the host has both, I think the correct default
>> behaviour is for the ULA address pair to be used.
> 
> As I put into the doc, I don't think that's quite right.
> 
> If both the source and dest ULAs are in the same /48 then I think the correct
> default is as you say (use ULA).
> 
> If the source and dest ULAs are in different /48's then I think the correct
> default is instead to use the non-ULA global, since there's no guarantee of
> routability between different /48s.  So unless configured otherwise, one
> has to assume it's far more problematic than a non-ULA global.

Yes, I agree, that is a case that would need to be handled by locally
installed rules if it was required to work (e.g. after a merger of
two intranets using different ULA prefixes). I doubt that default rules
can cover it.

    Brian

> 
> You'll find the above logic in the current 3484bis draft.
> 
> -Dave