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

["Marc Lampo" <[e-mail]>]

Hello,

I understand what you are writing, but is this the right way ?

The address selection table is, as far as I understand,
statically defined - not dynamically configurable (SLAAC or DHCPv6).
So, the suggestion is to adapt the table on every node of
the organisation.
In other words, every node in the organisation is somehow
 - via the address selection table - aware of the organisations
 network topology (VPN's and so).
Is this desired ?

Kind regards,

Marc Lampo


-----Original Message-----
From: Mark Andrews [mailto:[e-mail]] 
Sent: 19 March 2012 11:29 PM
Cc: Marc Lampo; 'Bob Hinden'; 'Brian Haberman'; [e-mail]; 'Arifumi
Matsumoto'; 'Dave Thaler'
Subject: Re: ULA scope [draft-ietf-6man-rfc3484-revise-05.txt]


In message <[e-mail]>, Mark Andrews
writes:
> 
> In message <01f401cd05dc$20914df0$61b3e9d0$@[e-mail]>, "Marc 
> Lampo" wri te
> s:
> > Allow me to clarify with an example.
> > 
> > In my IP(v4) experience, I have a customer with offices over 
> > multiple Continents - private address space in use everywhere - 
> > site-to-site VPN's (== connecting networks) connect the offices.
> > 
> > If I map to IPv6 this might be one /48 ULA range; Some networks in 
> > central HQ, others remotely, behind site-to-site VPN.
> > 
> > --> if one end-node in one network wants to reach another,
> >      in another network, its traffic must travel through the VPN.
> > 
> > Please observe that using public addresses (not using ULA) might do 
> > away with address selection "challenges"
> > but would imply that networks on all continents will have to be 
> > renumbered if the central HQ changes ISP (and hence : public IPv6 
> > addresses).
> > Something I'd like to avoid ...
> > 
> > Kind regards,
> > 
> > Marc Lampo
> 
> Well with a single ULA you have 65536 /64 sized networks to use where 
> ever you want.  You have ULA:0000/56 in Paris, ULA:0100/55 in New 
> York.  You don't have to keep things bit aligned but it helps.  65536 
> prefixes isn't a lot of routing information.  Think of it in IPv4 
> terms as 10/8 and you are handing out /24 for each subnet except you 
> know you won't need more than /24 ever.

Alternatively you can give each site its own ULA and you use non default
address selection rules.  Remember we are talking about the default rules
here.  There are billions of more homes than there are businesses.

They would use rules like the follow which give all the sites a common
label:

	::1      50   0
	ULA1:/48 45 100
	ULA2:/48 45 100
	ULA3:/48 45 100
	::/0     40   1
	2002::	 30   2
	fc00::	 0    3
 
Whereas the default rules generate a table like if it was multi-homed to
three sites:

	::1      50   0
	ULA1:/48 45   4
	ULA2:/48 45   5
	ULA3:/48 45   6
	::/0     40   1
	2002::	 30   2
	fc00::	 0    3
--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: [phone]                 INTERNET: [e-mail]