Re: Why has RFC 4941 been designed in such a way, that it might cause address conflicts?

Mohacsi Janos <mohacsi@niif.hu> Wed, 16 March 2011 10:44 UTC

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Date: Wed, 16 Mar 2011 11:45:21 +0100
From: Mohacsi Janos <mohacsi@niif.hu>
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To: Markus Hanauska <hanauska@equinux.de>
Subject: Re: Why has RFC 4941 been designed in such a way, that it might cause address conflicts?
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On Wed, 16 Mar 2011, Markus Hanauska wrote:

>
> On 2011-03-16, at 10:08 , Mohacsi Janos wrote:
>
>> Yes. DAD can fail, and you system log you will see.
>
>
> How will this help a network admin, when the system log says, that a 
> server that is supposed to have a certain fixed IP or a DHCP client, 
> that is also supposed to have a certain fixed IP (however, one assigned 
> by DHCP) cannot obtain this IP, because some other host with privacy 
> extension enabled is currently using this IP by plain coincident? How 
> can you resolve that problem? Running around the building and asking all 
> people with non-DHCP devices to please temporarily disconnect of the 
> network? Assigning a different IP to the server or the DHCP device does 
> not resolve the problem at all, because those are supposed to have a 
> certain IP and not any IP. Assigning a different IP to the stateless 
> device would work, but how can you know which of the maybe 100 stateless 
> devices on the network is the device that captured the IP?

The servers are "always" working. Newcomers cannot hijack their addresses 
since DAD will fail for them....

Best Regards,
 		Janos Mohacsi