Subject: [MEXT] Issue #4 Remove references to site-local addresses [George Tsirtsis <[email-masked]>]

From: "Charles E. Perkins" <[email-masked]>
Date: Fri, 27 Jun 2008 14:55:38 -0700

Hello folks,

I've reviewed the discussion about issue #4, and it seems to me that
a relatively painless compromise is available.  Namely, we could simply
delete the "SHOULD NOT" recommendation regarding the use of
ULAs as home or care-of addresses, while maintaining the cautionary
note about potential inaccessibility of correspondent nodes.

Here is the resultant text, which is otherwise almost identical to
George's text except for splitting a run-on sentence into two
sentences.

---------------------------------------------------------------------------
OLD TEXT:
=========
3.1. General Terms
...
   unicast routable address

      An identifier for a single interface such that a packet sent to it
      from another IPv6 subnet is delivered to the interface identified
      by that address.  Accordingly, a unicast routable address must
      have either a global or site-local scope (but not link-local).

NEW TEXT:
=========
3.1. General Terms
...
   unicast routable address

      An identifier for a single interface such that a packet sent to it
      from another IPv6 subnet is delivered to the interface identified
      by that address.  Accordingly, a unicast routable address must
      either be global IPv6 address or a unique local IPv6 address.

---------------------------------------------------------------------------

OLD TEXT:
=========
4.6. Site-Local Addressability

   This specification requires that home and care-of addresses MUST be
   unicast routable addresses.  Site-local addresses may be usable on
   networks that are not connected to the Internet, but this
   specification does not define when such usage is safe and when it is
   not.  Mobile nodes may not be aware of which site they are currently
   in.  It is hard to prevent accidental attachment to other sites, and
   ambiguity of site-local addresses can cause problems if the home and
   visited networks use the same addresses.  Therefore, site-local
   addresses SHOULD NOT be used as home or care-of addresses.

NEW TEXT:
=========
4.6. Unique-Local Addressability

   This specification requires that home and care-of addresses MUST be
   unicast routable addresses.  Unique-local IPv6 unicast addresses
   [RFC4193] may be usable on networks that use such non-globaly routable
   addresses but this specification does not define when such usage is
   safe and when it is not.  Mobile nodes may not be aware of which site
   they are currently making it hard to prevent accidental attachment
   to other sites, resulting in possible unrechability between the MN
   and the HA, when unique-local IPv6 routable addresses are used as
   care-of addresses.  CNs outside the MN's own site are unlikely
   to be reachable when unique-local IPv6 routable addresses are used
   as home addresses. If such addresses are used, however, according
   to [RFC4193], they are treated as any other global unicast IPv6
   address so, for the remainder of this specification, use of
   unique-local IPv6 unicast addresses is not differentiated
   from other globally unique IPv6 addresses.

---------------------------------------------------------------------------

OLD TEXT:
=========
10.4.2. Processing Intercepted Packets
...
                                            ... Packets addressed to
   the mobile node's site-local address SHOULD NOT be tunneled to the
   mobile node by default.

NEW TEXT (None: old text removed)
=========

---------------------------------------------------------------------------

OLD TEXT:
=========
11.3.1. Sending Packets While Away from Home
...
   o  While not at its home link, the mobile node MUST NOT use the Home
      Address destination option when communicating with link-local or
      site-local peers, if the scope of the home address is larger than
      the scope of the peer's address.

NEW TEXT:
=========
11.3.1. Sending Packets While Away from Home
...
   o  While not at its home link, the mobile node MUST NOT use the Home
      Address destination option when communicating with link-local peers.

---------------------------------------------------------------------------

OLD TEXT:
=========
11.5.4. Returning Home
...
                                ...The mobile node MUST multicast such a
   Neighbor Advertisement for each of its home addresses, as defined by
   the current on-link prefixes, including its link-local address and
   site-local address.

NEW TEXT:
=========
11.5.4. Returning Home
...
                                ...The mobile node MUST multicast such a
   Neighbor Advertisement for each of its home addresses, as defined by
   the current on-link prefixes, including its link-local address.

---------------------------------------------------------------------------

I recommend accepting the above changes in rfc3775bis-01, and
thereby resolving issue #4.

Regards,
Charlie P.

_______________________________________________
MEXT mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/mext

---

From: "George Tsirtsis" <[email-masked]>
Date: Sat, 28 Jun 2008 12:19:58 +0300

I am on vacation so I can not check your text right now, but I
proposed text for this when I brought up the issue, a long time ago.
Was anything wrong with it?

Thanks
George

---

From: "George Tsirtsis" <[email-masked]>
Date: Sat, 28 Jun 2008 12:22:27 +0300

Ah never mind, I just realised that the bulk of the text is what I
originaly proposed.

Sorry about that.
Thanks
George

---

From: [email-masked] (Arnaud Ebalard)
Date: Sat, 28 Jun 2008 13:45:40 +0200

Hi,

> note about potential inaccessibility of correspondent nodes.

great.

> <snip>
> <snip>
> <snip>
> <snip>
> <snip>

The changes you propose look fine.

Cheers,

a+