Re: ULAs in draft-arifumi-6man-rfc3484-revise-01

[Arifumi Matsumoto <arifumi at nttv6.net>]

Hi,

On 2009/06/22, at 19:01, Brian E Carpenter wrote:

> Hi,
>
> Section 2.3 of draft-arifumi-6man-rfc3484-revise-01 says:
>
> > 2.3.  To change ULA address scope to site-local
> >
> >   RFC 5220 Section 2.1.4, 2.2.2, and 2.2.3 describes address  
> > selection
> >   problems related to ULA.  These problems can be solved by changing
> >   the scope of ULA to site-local.
>
> This change will also create a new problem, for sites that configure a
> VPN to another partner site using ULAs on both sites, so that ULA-to- 
> ULA
> traffic can use the VPN. In this case ULA=global and longest match may
> well be the correct choice. If we change to ULA=site-local, then there
> must be a note that sites wishing to use ULAs for VPN communications
> will need to configure local 3484bis policy accordingly. (This is
> really the inverse of what is stated in RFC 5220.)


I failed to see why we need to change policy when ULA=site-local.
Could you please elaborate on this ?

And, if we adopt ULA=global scope and longest match with N=32 set,
the case 2.1.4 in RFC 5220, ULA can be chosen for the source address
to connect a server in the Internet ?

--
Arifumi Matsumoto
  Secure Communication Project
  NTT Information Sharing Platform Laboratories
  E-mail: arifumi at nttv6.net