Subject: [mobile-ip] Request to add an error code in RFC2794(NAI)

From: Samita Chakrabarti <[email-masked]>
Date: Mon, 2 Apr 2001 18:48:44 -0700 (PDT)

Hello,

We have encountered an operator's scenario where home-agent has
a bad behavior and assigns duplicate home-addr to multiple
mobile nodes visiting the same FA. Now the question is
how would the FA communicate this wrong behavior to MN ? 

The existing error codes in rfc2794 do not cover this particular
case. Also it's possible that a ill-behaving HA may allocate
addresses like 255.255.255.255 or 0.0.0.0 etc.

We think it will be good idea to have a specific error code
to cover this case. So, we are proposing an additional error code
in rfc2794 for this purpose:

INVALID_HOMEADDR    100    (Invalid homeaddress assignment) 

Thanks,
-Samita

---

From: Patrice Calhoun <[email-masked]>
Date: Tue, 3 Apr 2001 13:27:16 -0700 (PDT)

> addresses like 255.255.255.255 or 0.0.0.0 etc.

Indeed that is a good question. So MN1 registers and gets 10.1.1.1. Now MN2
registers and gets the same address (10.1.1.1). When the registration reply is
received on the FA, it detects that the HA is broken (well, it *thinks* it is
broken, but it MAY have rebooted and lost all of its state, hence the
duplicate address). The issue, as I understand it is that you want to
communicate this particular error to the mobile, correct?

> INVALID_HOMEADDR    100    (Invalid homeaddress assignment) 

I believe that I understand the problem, but let us keep in mind that this
error code is to protect against bad behavior, right? For that reason, I feel
uncomfortable having a new error code, because doing so sort-of implies that
it is ok to be broken. There are plentry of other ways an HA can be broken,
and there is no specific error code to cover that case, such as:

(e.g. NO_MORE_MEMORY_TO_ALLOCATE_VISITOR_ENTRY		666) :) :)

So, why would this one specific error be different?

Do others feel this is something that needs to be specified?

Chairs, would adding a new error code to RFC 2794 require that it re-cycle
back to proposed standard?

Thanks,

PatC