Re: [v6ops] New Version Notification for draft-ipversion6-loopback-prefix-00.txt

[t.petch <[e-mail]>]

----- Original Message -----
From: "Mark Andrews" <[e-mail]>
To: "Mark ZZZ Smith" <[e-mail]>
Cc: <[e-mail]>
Sent: Tuesday, February 17, 2015 1:23 AM

> The fundemental reason for 127.0.0.0/8 was to give each node a
> addresses block they could use. 127.0.0.1 evolved as the "standard"
> loopback address over time.  For the most part no one uses the rest
> of 127.0.0.0/8 but it is useful to have available.  That said any
> use of the rest of 127.0.0.0/8 has to be negotiated between the
> users.  You can't just grab 127.0.0.2 and hope that no one else is
> using it for IP traffic.

Mark

I would refer you to RFC5782 and RFC6471 for a discussion on the use of
127.0.0.2 (and ::FFFF:7F00:2 ).

Perhaps those RFC should have included an IANA Considerations:-(

Tom Petch








>
> In IPv6 we had both link local and site local addresses from the
> get go.  These gave the operator addresses they could use.  They
> were also slightly more complicated than a GUA as you needed to
> specify scope.  We now have ULA addresses which gets rid of the
> need to specify scope.  Just like with 127.0.0.2 you need to negotiate
> the use of a address.
>
> Reserving a new block of addressing in IPv6 will not stop the need
> to negotiate address use.
>
> If you need truly automatic assignment you need to go to IANA or a
> RIR (e.g. ARIN and 100.64/10) and request a block for a specific
> purpose.  There is no other way to do truly automatic.
>
> Mark
>
> In message
<[e-mail]>, Mar
> k ZZZ Smith writes:
> > So the fundamental problem is 'configured like this'. It's a manual
operation
> >  to generate and apply a ULA. ULAs on loopbacks aren't going to well
known or
> >  ubiquitous.
> >
> > If you want something to be used you need to make it easy, and the
best way t
> > o make something easy is to make it automatic.
> >
> > The value in 127/8, ::1 and a larger IPv6 loopback prefix is that it
is or wo
> > uld be automatically configured by the OS, with operator
intervention. It's a
> > lways there, and always available to use. The 4.1c/2.9BSD people
though there
> >  was value in automatic configuration of the loopback address on a
loopback i
> > nterface, way back in 1982/1983:
> >
> >
http://minnie.tuhs.org/cgi-bin/utree.pl?file=2.9BSD/usr/net/sys/net/if_l
oop.c
> >
> >
http://minnie.tuhs.org/cgi-bin/utree.pl?file=4.1cBSD/a/sys/netinet/if_lo
op.c
> >
> >
> >
> > ----- Original Message -----
> > From: Mark Andrews <[e-mail]>
> > To: David Conrad <[e-mail]>
> > Cc: Mark ZZZ Smith <[e-mail]>; "[e-mail]"
<v6ops@ietf.
> > org>
> > Sent: Tuesday, 17 February 2015, 10:22
> > Subject: Re: [v6ops] New Version Notification for
draft-ipversion6-loopback-p
> > refix-00.txt
> >
> >
> > We don't need *more* reserved address for this.  This is from my
> > laptop and it has been configured like this for years.
> >
> > Yes, I have a ULA site on my loopback interface.  If your loopback
> > interface does not support this it is broken.
> >
> >
> > Mark
> >
> > lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
> >     options=3<RXCSUM,TXCSUM>
> >     inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
> >     inet 127.0.0.1 netmask 0xff000000
> >     inet6 ::1 prefixlen 128
> >     inet 10.53.0.1 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::1 prefixlen 64
> >     inet 10.53.0.2 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::2 prefixlen 64
> >     inet 10.53.0.3 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::3 prefixlen 64
> >     inet 10.53.0.4 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::4 prefixlen 64
> >     inet 10.53.0.5 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::5 prefixlen 64
> >     inet 10.53.0.6 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::6 prefixlen 64
> >     inet 10.53.0.7 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::7 prefixlen 64
> >     inet 10.53.0.8 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::8 prefixlen 64
> >     inet 10.53.0.9 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::9 prefixlen 64
> >     inet 10.53.0.10 netmask 0xffffffff
> >     inet6 fd92:7065:b8e:ffff::10 prefixlen 64
> >
> > --
> > Mark Andrews, ISC
> > 1 Seymour St., Dundas Valley, NSW 2117, Australia
> > PHONE: [phone]                 INTERNET: [e-mail]
> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: [phone]                 INTERNET: [e-mail]
>
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