Re: [DNA] Re: Flash renumbering

[Sathya Narayanan <sathya@research.panasonic.com>]

Erik Nordmark wrote:

> Sathya Narayanan wrote:
>
>> I believe I was going for #2 - not that I clearly thought about it like
>> this ;-)
>>
>> I think leaving it as #1 is bad, #3 is too much and will put unnecessary
>> restrictions on normal operation to address a 'low-probability' problem,
>> hence we are left with #2.
>
> FWIW I'm of the same opinion.
>
>> Agreed. Also, the periodic RA, if it is complete will not include P1 and
>> that can be used as indication also. If N CompleteRA messages are
>> received without the prefix, start getting suspicious.
>
> That is an interesting idea, because when there is intermittent
> connectivity and packet loss, it is more likely to occur for the hosts
> than for router-to-router communication (assuming the traditional
> deployment of routers on a wired network - a wireless mesh of routers
> would potentially change this).
>
> Thus the router not hearing a prefix from another router for 1.5 hours
> is a more reasonable indication that the prefix can be dropped, than a
> host not hearing it for 1.5 hours.
>
> But what would we do in the case when all the prefixes don't fit in
> one RA hence the complete bit can not be set?

I know this is always an issue. But, isn't it a general problem about
CompleteRA which we need to think about either way?

I don't remember why we decided to remove the #prefixes field from the
DNAO.  I thought most of us felt that this field will help out with
being able to send the prefixes in two or more RA if they don't fit in a
single RA.

So, let me bring #prefixes back instead of the complete bit, here is
what I propose when the prefixes don't fit in one RA:
1) Divide the prefixes into groups with atleast one common prefix so
that each group will fit in a single RA.
2) Set the #prefixes field in the DNAO to the total number of prefixes
(The semantics for this is "This is the number of prefixes on the link
*I* know of").

>> In conclusion, I suggest we create some text based on your suggestion
>> from the previous email as a starting point.
>
> ok

So, do you want me to write it? Brett?

- Sathya