Capwap Mailing List: Re: IESG Review Comment T22

[Pat Calhoun (pacalhou) (pcalhoun]

Ok, I understand the question now. This message element is used by the
WTP to tell its AC that someone has hijacked its IP address - so we
already know the MAC address of the WTP. The MAC address that is
communicated in the message element is that of the other host that is
using the WTP's IP address. The text reads:

   The Duplicate IPv4 Address message element is used by a WTP to inform
   an AC that it has detected another IP device using the same IP
   address that the WTP is currently using.

The length field is used to specify whether the MAC address is 6 or 8
octets, [EUI-48] and [EUI-64], respectively:

   Length:  The length of the MAC Address field.  The following formats,
      and lengths, are supported [EUI-48] and [EUI-64].

PatC

-----Original Message-----
From: Romascanu, Dan (Dan) [mailto:dromasca [at] avaya.com] 
Sent: Tuesday, June 17, 2008 5:11 AM
To: Pat Calhoun (pacalhou); capwap [at] frascone.com
Subject: RE: [Capwap] IESG Review Comment T22

Let me try to clarify my question. 

The length field indicates the length of a list of MAC addresses that
were detected to be behind duplicate IP addresses (IPv4 and IPv6
respectively). 

Why would this length be anything but 12 (i.e. 2 MAC addresses?)

- do we need to support more the detection of more than two addresses? 
- why would length of MAC addresses behind IPv4 addresses be different
than the length of the addresses behind IPv6 addresses? 

Dan


> -----Original Message-----
> From: Pat Calhoun (pacalhou) [mailto:pcalhoun [at] cisco.com]
> Sent: Monday, June 16, 2008 6:36 PM
> To: capwap [at] frascone.com
> Subject: [Capwap] IESG Review Comment T22
> 
> All,
> 
> Here is the IESG Review Comment:
> 
>    T22 - Sections 4.2.24, 4.2.25 - why are the length field defined as
> >= 12, and >=
>    24 respectively. Is this triplicate addresses? Or more? 
> And if such cases exist, is 
>    this important to detect and report all in one message? 
> 
> I'm not sure that the comment makes sense since the length of the 
> field is correct. In both cases we assume a minimum MAC Address length

> of 6 octets. I believe this comment is invalid.
> 
> PatC
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