Re: Newbie Question about addressing impacts

If I recall correctly, the policy table can list prefixes
explicitly in priority order. So for mh, than means that
policy can say: if A fails, try B; if B fails, try C.

But I may be misremembering 3484, it's been a while...

    Brian


marcelo bagnulo braun wrote:
> Hi Brian, Arifumi,
> 
> I am not sure that the policy table falls under this particular 
> component, since as i see it, the policy table is more related with 
> locator selection when there are no failures and it is used as a mean to 
> express administrative prefferences.
> Anyway, as i understand it, Arifumi is considering mechanisms to 
> distribute RFC3484 policy table, so this is not really related to 
> locator selection, but rather with centralized policy management.
> IMHO this will be a requirement, especially as the sites grow bigger, 
> because manually configuring the policy table of each hosts doesn't 
> seems a reasonable approach when there is a considerable number of hosts.
> Well, in any case, i can see basically two options to provide automatic 
> configuration of RFC3484 policy table:
> - router Advertisement
> - dhcp option
> 
> the porblem with RA is that the full policy table has to fit in a single 
> RA message, since imho the distribution of the policy table should be 
> atomic (having only part of the policy table configure may cause 
> undesired behaviour), in addition, RA requires the configuration of the 
> policy table in at least one router per link, which may be cumbersome
> the problem with dhcp is that you need a dhcp server, but it provides 
> most of the desired features AFAICS
> 
> imho, a policy distribution mechanism will be needed at some moment.
> We have made a couple of implementations in linux of the two policy 
> table distribution mechanisms, one using dhcp and another one using RA, 
> to see how this work.
> If anyone is interested, we can discuss it.
> 
> Regards, marcelo
> 
> El 12/08/2004, a las 16:26, Brian E Carpenter escribió:
> 
>> One of the components we have already identified (see the minutes
>> from San Diego) is
>>
>>  Locator selection after a failure has been detected / Choose new 
>> address pair
>>
>> RFC 3484 policy distribution might be a possible solution
>> for that component. We aren't chartered to do basic design in
>> this WG, but it would certainly be good to see proof-of-concept
>> for this (and every) component.
>>
>>      Brian
>>
>>
>> Arifumi Matsumoto wrote:
>>
>>> Oops, I forgot to send CC to multi6.
>>> -- 
>>> Hi marcelo,
>>>
>>>> Well, even if you do a per host locator selection you can still 
>>>> manage policy in a centralized fashion, if we define proper 
>>>> mechanisms to perform policy distribution, for instance a dhcp 
>>>> option for distributing RFC3484 policy table or something similar. 
>>>> However, i don't know how you can enforce policy in a centralized 
>>>> manner when locator selection is performed by the end hosts.
>>>
>>> I believe that such a mechanism for policy distribution
>>> is really important. By making use of the existing RFC3484
>>> framework, IMHO we can develop much manageable multi-home
>>> environment in a simple and easy manner.
>>> Now I'm working on this mechanism to publish a new I-D.
>>> But I'm not sure such kind of topic is appropriate for
>>> this WG or not. I believe this part of the technology should
>>> be necessary for some of the proposals discussed here, though.
>>> -- 
>>> Arifumi Matsumoto
>>>     Ubiquitous Computing Project
>>>     NTT Information Sharing Platform Laboratories
>>>     E-mail: [email protected]
>>
>>
> 
> 
>