Subject: Re: [mobile-ip] 0.0.0.0 src address

From: "Alper E. YEGIN" <[email-masked]>
Date: Sun, 2 Dec 2001 00:05:45 -0800

Marc,

>  > The foreign agent should use the link-layer address of the incoming
(from
>  > MN) packet
>  > to send back the responds to the MN. So, FA can send a packet with
0.0.0.0
>  > IP destination
>  > address and MN's link-layer address as the destination MAC address.
>  >
>  > For that, foreign agent should note the source link-layer address of
the
>  > incoming packet.
>  >
>  > The same can also happen with simple rotuer discovery (sending router
>  > solicitation, and
>  > receiving router advertisement). Please see rfc1256.
>
> I don't see where RFC 1256 supports the concept of *sending* to a
> destination address of 0.0.0.0 so let me know if I've missed
> some text.   It clearly allows a router solicitation with a
> *source* address of 0.0.0.0 from a host that hasn't yet determined its
> own address.  But the router advertisement response in such a case
> doesn't go to 0.0.0.0, which would be a violation of the RFC as I read
> it, but to a configured address.  Here's the text excerpt from the RFC
> in section 4.3 that clearly covers the source 0.0.0.0 address case in
> the second sentence:
>
>    In addition to the periodic, unsolicited advertisements, a router
>    sends advertisements in response to valid solicitations received on
>    any of its advertising interfaces.  A router may choose to unicast
>    the response directly to the soliciting host's address (if it is not
>    zero), or multicast it to the interface's configured
>    AdvertisementAddress; in the latter case, the interface's interval
>    timer is reset to a new random value, as with unsolicited
>    advertisements.  ...

You are right. I missed this. I had blindly assumed advertisement must be
unicasted
to the solicitor. (especially because it's technically doable...)

>
> The rationale for a host sending with a source address of 0.0.0.0
> appears to be implied in section 5.3 as a mechanism to allow overlap of
> the host's address and router discovery processes to occur in
> parallel.  Such a host presumably provokes an earlier multicast router
> advertisement by sending the solicitation with its 0.0.0.0 source
> address rather than waiting for the next periodic advertisement or
> until the host has an address.

This is interesting. A solicitation can cause a multicast advertisement. Not
desirable for wireless systems. Bandwidth issues, and also waking up dormant
nodes issue.

Thanks Marc.

alper

>    -- Marc --

---

From: "Alper E. YEGIN" <[email-masked]>
Date: Sun, 2 Dec 2001 00:14:20 -0800

Folks,

New version of L2 triggers draft is available:

http://www.ietf.org/internet-drafts/draft-manyfolks-l2-mobilereq-01.txt

Supporting Optimized Handover for IP Mobility - 
Requirements for Underlying Systems 

   Abstract 
    
   A critical factor in achieving good performance for IP mobility 
   protocols is the design of L2 handover. Handover occurs when a 
   Mobile Node moves from one radio Access Point to another. If the new 
   radio Access Point is associated with a new subnet, a change in 
   routing reachability may occur and require L3 protocol action on the 
   part of the Mobile Node or Access Routers. If no change in subnet 
   occurs, the Access Point may still need to take some action to 
   inform the Access Router about a change in on-link reachability. In 
   either case, prompt and timely information from L2 to the parties 
   involved about the sequencing of handover can help optimize handover 
   at the IP level. This draft discusses requirements for an L2 
   handover protocol or API to support optimized handover. 

Enjoy.

alper

---

From: Behcet Sarikaya <[email-masked]>
Date: Sun, 02 Dec 2001 16:13:19 -0600

Alper and WG Chairs,
  We have a draft which is very much related to this one at:

http://search.ietf.org/internet-drafts/draft-guri-seamoby-paging-triggers-00.txt

we had submitted it to SeaMoby WG because Jim's draft was discussed in
London at Seamoby WG, so there is some confusion.

My question is what is the next step at SLC? Will this be discussed at MIP
WG, or is it in Seamoby WG domain as it was in London?

  Thanks in advance for any clarification.

--
Behcet

---

From: "James Kempf" <[email-masked]>
Date: Sun, 2 Dec 2001 15:32:11 -0800

Behcet.

The Wireless Directorate has been discussing what to do about your draft
and ours. We have not yet quite completed the discussion, but I am
hoping that we will reach some kind of conclusion in SLC.

            jak

----- Original Message -----
From: "Behcet Sarikaya" <[email-masked]>
To: <[email-masked]>; "seamoby" <[email-masked]>
Sent: Sunday, December 02, 2001 2:13 PM
Subject: Re: [mobile-ip] L2 triggers draft

>   We have a draft which is very much related to this one at:
http://search.ietf.org/internet-drafts/draft-guri-seamoby-paging-trigger
s-00.txt

---

From: "Alper E. YEGIN" <[email-masked]>
Date: Sun, 2 Dec 2001 16:28:21 -0800

My opinion is, among existing working groups it best fits PILC.

But, if we want to do a better job (more than L2 triggers), then I'd
recommend forming a new Sub-IP working group: IP over Wireless.

My 0.02 cents.

Seamoby folks, please note that the new version of L2 triggers draft is at:

alper

---

From: subir Das <[email-masked]>
Date: Mon, 03 Dec 2001 18:57:37 -0500

Alper,
Pl. send your talk (for 10 mins) slides latest by Dec 10th.

Thanks,

Subir

---

From: Gopal Dommety <[email-masked]>
Date: Mon, 03 Dec 2001 16:36:35 -0800

A newer version of the Draft that addresses a lot comments sent to me can 
be found at:

http://people.nokia.net/~patil/Internet_Drafts/draft-ietf-mobileip-fast-mipv6-04.txt

Thanks
Gopal

---

From: subir Das <[email-masked]>
Date: Tue, 04 Dec 2001 09:14:48 -0500

Sorry about this. This is same "reply to" problem.

Subir