Re: new issue: [LL36] Combine and rework section 1.7 and 2.11 to be clearer

Alex Karahalios <[email protected]> Tue, 16 Dec 2003 13:51:01 -0700
Newsgroups gmane.ietf.zeroconf
Message-ID <[email protected]>
Ralph,

Sorry to imply you are proposing this text since it's part of section 
1.7 already...

Alex Karahalios


On Dec 16, 2003, at 1:19 PM, Alex Karahalios wrote:

> Ralph,
>
> Yes, I understand this, but I think the phrase you are proposing, a 
> host "MUST cease advertising the availability of the Link-Local IPv4 
> address through whatever mechanisms that address had been made known 
> to others," will make it such that a new LL IPv4 device will not be 
> able to interoperate on the network.
>
> Take the case of a printer using mDNS, for example. A new device would 
> only get routable address information from the printer, but the new 
> device is only configured for LL IPv4 and thus is shut out of 
> communicating with the printer.
>
> Alex Karahalios
>
> On Dec 16, 2003, at 11:09 AM, Ralph Droms wrote:
>
>> Well, section 1.9 of draft-ietf-zeroconf-ipv4-linklocal-10.txt,
>> "Communication with Routable Addresses", describes how two devices can
>> communicate in the case you describe, where one device has a routable
>> address and one device has a Link-Local IPv4 address.
>>
>> Of course, there's a difference between "finding" and "communicating 
>> with".
>> "Finding" printers is out of scope for Link-Local IPv4, so
>> draft-ietf-zeroconf-ipv4-linklocal-10.txt doesn't address how the 
>> computer
>> determines the printer's address, regardless of whether the printer 
>> is using
>> a routable address or a Link-Local IPv4 address.
>>
>> - Ralph
>>
>> At 10:25 AM 12/16/2003 -0700, Alex Karahalios wrote:
>>> Given the below text which specifies the a host "MUST cease 
>>> advertising the availability of the Link-Local IPv4 address", could 
>>> some explain how I would be able to make use of LL IPv4 addressing 
>>> in the following circumstances:
>>>
>>> Let's say a printer stops advertising LL IPv4 addresses because it 
>>> obtains a DHCP address. A new computer is introduced into the 
>>> network that wants to print, but it cannot obtain a routable 
>>> address, so it configures a LL IPv4 address. How is the new computer 
>>> suppose to find the printer if the printer has stopped advertising 
>>> its LL address?
>>>
>>> I've asked a similar version of this question before and was told 
>>> that there are provisions in draft to address this, but the follow 
>>> text preclude this.
>>>
>>> Thanks,
>>>
>>> Alex Karahalios
>>>
>>> On Dec 16, 2003, at 10:00 AM, Ralph Droms wrote:
>>>
>>>>    If a host finds that an interface that was previous configured 
>>>> with
>>>>    a Link-Local IPv4 address is now configured with a valid routable
>>>>    address, the host MUST always use the routable address when
>>>>    initiating new communications, and MUST cease advertising the
>>>>    availability of the Link-Local IPv4 address through whatever
>>>>    mechanisms that address had been made known to others.  The host
>>>>    SHOULD continue to use the Link-Local IPv4 address for
>>>>    communications underway when the routable address was configured,
>>>>    and MAY continue to accept new communications addressed to the
>>>>    Link-Local IPv4 address.  Ways in which a valid routable address
>>>>    might be configured for the interface include:
>>
>