Subject: [mobile-ip] RE: RFC2002bis interpretation question

From: "Mohamed Khalil"<[email-masked]>
Date: Tue, 5 Feb 2002 09:55:57 -0600

Hi George,

The way we have implemented that is that when the mobile node sees this bit
in the advertisement it must use the foreign agent care-of address in its
registration. The mobile node will use the home address as a source address,
except in case of ingress filter will use the reverse tunnel with FA care-of
address as a source address.

Mohamed Khalil
Nortel Networks

-----Original Message-----
From: George Tsirtsis [mailto:[email-masked]]
Sent: Tuesday, February 05, 2002 6:54 AM
To: Mobile-Ip (E-mail)
Subject: RFC2002bis interpretation question

Hi all

I am trying to figure out how implementers have interpreted the Rbit part of
rfc2002. I have asked a few people privately and I do not get identical
feedback so some discussion here maybe helpful. 

I remind you that if the Rbit is set in a Foreign Agent Advertisement the
MIP client is required to register through the Foreign Agent even if it has
access to a collocated address...
But what does that mean exactly?
1. Should the client register its Collocated care-of-address (and thus
ignore the advertized CoA) but send the registration request to the FA and
the FA forwards it to the HA?
2. Should the client register with the care-of-address advertised in the
advertisement? If this is the case, can the mobile now also use a collocated
care of address as source address for some traffic??

Is one of the above the "correct" behavior? How does your MIP client
implementation behave and what does your Foreign Agent implementation
expect?

Are you aware of any interoperability tests in this area?

Thanks for your help
George
P.S: I am interested about what the intention of the spec is but also about
how current Mobile Node and Foreign Agent implementations behave and what
they expect so let me know privately if you do not want to do that on the
mailing list.

---

From: "Narjala, Ranjit S" <[email-masked]>
Date: Thu, 7 Feb 2002 10:04:31 -0800

Our implementation (at Intel) supports both methods - registering with the
FA via a colocated care-of address, as well as a FA care-of address. The
spec, as has been said before, left this open, and we thought it would be
wise to support both. 

In our implementation, we register using the FA care-of address by default
(reason below), but the user has the option to force the MN to use the
colocated care-of address when in this situation. 

In the interests of saving time on handoffs, we've noticed that registering
with the FA care-of address is better. When a link comes up (ethernet cable
plugged in to a wired NIC, for example), Agent Discovery can usually be
completed faster than obtaining a DHCP address (the colocated address), and
then registering with the FA using the FA care-of address is in most cases
significantly faster than waiting to obtain a DHCP address and then
registering with the FA using that colocated address.

My two cents.

Regards,
- Ranjit

-----Original Message-----
From: eskl [mailto:[email-masked]]
Sent: Thursday, February 07, 2002 8:14 AM
To: [email-masked]
Subject: RE: [mobile-ip] RFC2002bis interpretation question

Our MN is also using the FA care-of-address. 

espen
Espen Klovning  
Birdstep Technology ASA 
www.birdstep.com

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]] On Behalf Of Bjorn
Andersson
Sent: 7. februar 2002 15:41
To: [email-masked]
Subject: Re: [mobile-ip] RFC2002bis interpretation question

On Thu, Feb 07 2002, at 15:29:46 +0100, Hans Sjöstrand wrote:
> We register with the care-of-address advertised in the advertisement.
We use
> the home address as source address. Collocated care-of-address we only
use when
> registering directly with HA.

This is actually what our MN implementation does also, although I
interpreted it differently in my previous mail. So now we have three
MNs registering the FA care-of address.

  Björn

-- 
Björn Andersson <[email-masked]>                       +358 50 341 2556
Lifix Systems Oy <http://www.lifix.fi/>                 PGP id 5AFC144B
Yliopistonkatu 5, 3rd floor; FIN-00100 Helsinki