legacy /8

Steven Bellovin smb at cs.columbia.edu
Sat Apr 3 09:00:54 CDT 2010

On Apr 3, 2010, at 9:55 13AM, jim deleskie wrote:

> Not sure the IETF looked at it or not, but personally I'm one of those
> people that has never accepted a solution just because, its the only
> option there.  I haven't always won my battles, but never just give in
> :)

Guess what -- this solution, or things isomorphic to it, were indeed considered at the time.  See RFC 1955:

   The basic idea is that inter-domain routing be done by routing on
   autonomous domains (AD).  The key is how this is done.  The mechanism
   to do this is for the border routers to encapsulate the original IP
   datagrams with another IP header.  The source and destination
   addresses in the new header (I will call it the AD-Header from here
   on) represent the source and destination ADs.

Sound familiar from this discussion?

> -jim
> On Sat, Apr 3, 2010 at 3:47 AM, Jim Burwell <jimb at jsbc.cc> wrote:
>> On 4/2/2010 19:13, George Bonser wrote:
>>>> -----Original Message-----
>>>> From: Jim Burwell [mailto:jimb at jsbc.cc]
>>>> Sent: Friday, April 02, 2010 6:00 PM
>>>> To: nanog at nanog.org
>>>> Subject: Re: legacy /8
>>>> So, jump through hoops to kludge up IPv4 so it continues to provide
>>>> address space for new allocations through multiple levels of NAT (or
>>>> whatever), and buy a bit more time, or jump through the hoops required
>>>> to deploy IPv6 and eliminate the exhaustion problem?  And also, if the
>>>> IPv4 space is horse-traded among RIRs and customers as you allude to
>>>> above, IPv6 will look even more attactive as the price and
>>> preciousness
>>>> of IPv4 addresses increases.
>>> No problem,  everyone tunnels v4 in v4 and the "outer" ip address is
>>> your 32-bit ASN and you get an entire /0 of "legacy" ip space inside
>>> your ASN.  Just need to get rid of BGP and go to some sort of label
>>> switching with the border routers having an ASN to upstream label table
>>> and there ya go. Oh, and probably create an AA RR in DNS that is in
>>> ASN:x.x.x.x format.  Increase the MTU a little and whammo!  There ya go!
>>> Done.
>>> :)
>> So essentially add 32-bits to the IPv4 address, used as a ASN, and use
>> legacy V4 on the "backbone" which tunnels everything, so the entire
>> intra-ASN internet has to go through v4-in-v4 tunnels.  A few "little"
>> changes to DNS, and voila!  And of course, there's no "devils in the
>> details" we have to worry about.  Heck.    Just quote that last post up
>> and submit it as an RFC to replace the IPv6 RFCs!  :-)
>> Seriously though, would that really be easier to implement, or be better
>> than IPv6 as this point?  I'd think the IETF would probably have
>> considered solutions like that, but IPv6 is what we got.  So best learn
>> to love it.  :P
>> -Jim

		--Steve Bellovin, http://www.cs.columbia.edu/~smb

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