Redploying most of 127/8 as unicast public

Fri Nov 19 14:54:08 UTC 2021

> On Nov 17, 2021, at 21:33 , Joe Maimon <jmaimon at jmaimon.com> wrote:
> 
> 
> 
> Mark Andrews wrote:
>> 
>>> On 18 Nov 2021, at 11:58, Joe Maimon <jmaimon at chl.com> wrote:
>>> 
>>> 
>>> 
>>> Mark Andrews wrote:
>>>> It’s a denial of service attack on the IETF process to keep bringing up drafts like this that are never going to be approved.  127/8 is in use.  It isn’t free.
>>> There are so many things wrong with this statement that I am not even going to try to enumerate them.
>>> 
>>> However suffice it to say that drafts like these are concrete documentation of non-groupthink and essentially you are advocating for self-censorship and loss of historical perspective.
>> I’m advocating for not taking address away that have been allocated for a purpose.  No one knows what the impact of doing that will be.  Perhaps we should just take back 216.222.144.0/20?  You obviously think taking back address that are in use to be a good thing.  This is similar to taking back other address that are allocated but not advertised.
> 
> I am advocating for serious discussion on the merits, and only the merits, of each individual idea and proposal and to respect those willing to put in the effort even while likely knowing of the undeserved scorn bound to come their way from those who choose not do as I would advocate them doing.
> 
> And I think the basic contention is that the vast majority of 127/8 is not in use. Apples to oranges, indeed.

This contention is provably false for some definitions of “in use”.

>> You can script is to the same extent that you can hard code 127/8 addresses.  I’ve used ULA addresses but conceptually they are the same.  The lo0 interface also has more that 127.0.0.1 IPv4 addresses on it.
>> 
>> % ifconfig lo0 inet6
>> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
>> 	options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
>> 	inet6 ::1 prefixlen 128 .
>> 	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
>> 	inet6 fd92:7065:b8e:ffff::1 prefixlen 64
>> 
> Thats twice now you have suggested that ULA and LLA are an exact substitute for dedicated system loopback prefix.

In what way would the LLA or ULA above be meaningfully different from 127/8 as deployed?

> At the very least, it is semantically not.

How so?

> Doesnt IPv6 deserve its own instead of squatting on IPv4?

I don’t see any “squatting on IPv4” here.

Since, as you point out, use of the other addresses in 127.0.0.0/8 is not particularly widespread, having a prefix
dedicated to that purpose globally vs. allowing each site that cares to choose their own doesn’t seem like the best
tradeoff.

Owen