Re: [addr-select-dt] Proposed default policy table

[Aleksi Suhonen <[e-mail]>]

On 07/12/10 07:38, Arifumi Matsumoto wrote:
>> I have one other topic to add which I can't remember whether I posted about recently or not, so apologies if I'm repeating myself.
>>
>> In undertaking some work recently on router-based hints for address selection, we found that we could improve address selection behaviour for hosts by using a new ICMP-based message to query a router or route server for an ordered list of address pairs to use for given candidate addresses.  The issue that came up was that if the host were to cache the result, and we chose to cache it within the RFC3484 policy tables, can we change/augment the current syntax/format to accommodate that?
>
> That approach also should have an issue of policy merge/conflict.
>
> When we think about merging process, we may have to think about this
> kind of approach, if we think it looks like some advantages in merging.

The Linux Way of recent days seems to be to replace /etc/<software>.conf 
with /etc/<software>.d/*.conf so in Linux specifically you could 
implement it like this:

/etc/gai.conf:
1. default rules that can be overriden
2. include instruction for /etc/gai.d/*.conf
3. system wide rules that can't be overriden

And then your address selection policy update daemon(s) would update 
their own file(s) in /etc/gai.d/ safely.

I don't have a good understanding on how other operating systems have 
implemented RFC3484 so I can't comment how universal this would be.

-- 
	Aleksi Suhonen
	Department of Communications Engineering
	Tampere University of Technology