----- Original Message -----
From: "Christian Huitema" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>; "Jeroen Massar" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Wednesday, April 02, 2003 2:14 PM
Subject: Globally unique link prefix alternative to site-locals
> The "anti-SL" arguments are primarily arguments aainst using ambiguous addresses.
> Ambiguous addresses are a royal pain in hosts
that connect to multiple sites, either simultaneously or over time -- the applications
need extra logic, and that creates bugs. But
we clearly have an issue in the case of disconnected sites, intermittently connected
sites, and ad hoc networks.
>
> The "let's pick a prefix" argument is probably OK for large "managed" sites. In
> fact, most of the large sites have at least one
IPv4 address and can pick a prefix; they could even obtain a provisional allocation
from a friendly ISP. But this leaves out the
small sites, the ad hoc networks, the unmanaged sites. However, if we just look at
these small sites, we can easily get unambiguous
*link* prefixes of the form:
> <some-16-bit-prefix><unique 48 bit number>::/64
> In a small site, these prefixes can be autoconfigured by routers, and then published
> in the IGP. If there are several routers on
the same link, they can either elect a master prefix or just advertise one prefix
each. Having unique per-link prefixes has quite a
few advantages:
>
> - We get actual zero-configuration, a site can be just switched on.
> - Local connectivity can be used for adding a global addressing plan when
> the site joins the Internet.
> - Hosts can be multihomed at will; there is enough information in the
> address to find the right exit.
> - The addresses remain valid if a site is split, or if two sites are merged.
> - Unreachability is enforced by firewalls, not by bits in the address.
> - Since the link prefix is a /64, there is zero chance of having a nasty ISP
> leak it to the Internet.
> - If the /16 is well known, it can be plugged as "least preferred" in the
> address selection rules.
>
> Is anyone interested in pursuing this design?
>
> -- Christian Huitema
>
<some-16-bit-prefix><unique 48 bit number>::/64
Are you on the AM Internet or the FM InterNAT ?
128-bit DNS AAAA Record Flag Day Formats
2003:[IPv4]:[SDLL.OFFF.FFFF.TTTT]:[64-bit IPv8 or IPv16 Persistent Address]
[YMDD]:[IPv4]:[SDLL.OFFF.FFFF.TTTT]:[64-bit IPv8 or IPv16 Persistent Address]
1-bit to set the Reserved/Spare ("AM/FM") bit in Fragment Offset [S]
1-bit to set the Don't Fragment (DF) bit [D]
2-bits to select 1 of 4 common TTL values (255, 128, 32, 8) [LL]
1-bit for Options Control [O]
7-bits to set the Identification Field(dst) [FFFFFFF]
4-bits to set the TOS(dst) Field [TTTT]
Default SDLL.OFFF.FFFF.TTTT = 0000.0000.0000.0000
FFF.FFFF.TTTT = GGG.SSSS.SSSS
http://www.ntia.doc.gov/ntiahome/domainname/130dftmail/unir.txt
IPv8
0QQQQGGGSSSSSSSS[32-bits][Port]
IPv16
0QQQQGGGSSSSSSSS[32-bits][Port]
1AAAAAAAAAAAAAAA[32-bits][Port]
A...A=ASN=32769...65535
Jim Fleming
http://www.IPv8.info
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