Re: [DNA] Issue 6: DNAHostLinkIDList

[Greg Daley <Greg.Daley@eng.monash.edu.au>]

Hi JinHyeock, 

If the router has an address prefix configured for routing (local delivery),
even if it is not configured for stateless address autoconfiguration, it
can advertise it as a learned prefix.

This could be an automatic process.

If the router doesn't have any prefixes configured for routing, then
I would prefer not requiring it to have a prefix configured just for the
purpose
of link identification.

How about we say:

"...
In some circumstances, such as when DHCPv6 is used, a router may not be
configured
to advertise prefixes in Prefix Information Options [RFC3315].  If a router
interface is configured with a non link-local prefix and does not send
Prefix Information Options, each Router Advertisement it sends MUST
contain at
least one prefix in a Learned Prefix Option for the purposes of Link
Identification.

If the router has not learnt any valid Prefix Information Options this
prefix MUST
be one of its own locally configured non link-local prefixes, and the
"Complete"
flag MUST NOT be set in the RA.

If this router learns valid prefixes from a Prefix Information Option,
it SHOULD
advertise this instead, advertising the "Complete" flag if all of the
link's PIO
advertised prefixes are readvertised in LPOs.
..."

Of course, learned prefixes aren't readvertised, and multiple non
PIO-advertising
routers may advertise disjoint LPOs.

In that case, the Complete Flag isn't set, and the routers provide the
prefix only
to assist CPL hosts in determining link change.

The system reverts to nromal operation if even one router advertises
with a PIO.

Greg

----- Original Message -----
From: JinHyeock Choi <jinchoe@gmail.com>
Date: Monday, January 29, 2007 1:44 pm
Subject: Re: [DNA] Issue 6: DNAHostLinkIDList
To: Sathya Narayanan <sathya@research.panasonic.com>
Cc: Dna <dna@eng.monash.edu.au>

> Dear Sathya
> 
> Thanks for your trouble advancing the work.
> 
> > I still haven't closed Issue 2:, changes to support Stateful
> > autoconfiguration scenario. The current text depends on DHCP 
> CONFIRM to
> > address this scenario. I am still uncomfortable requiring 
> configuration> of each router on the link with the smallest prefix -
> a sysadmin then
> > becomes responsible for keeping track of the smallest prefix and
> > updating the configuration each time.
> 
> Sysamin doesn't have to keep track of the smallest prefix and
> configure it to each router manually.
> 
> Sysamin only have to configure a router to advertise at least one
> prefix. Then, after a while, the routers on the same link, upon
> hearing the prefixes from each other, will pick the smallest prefix
> and advertise it in either PIO or LPIO.
> 
> Thanks for your kind consideration.
> 
> Best Regards
> 
> JinHyeock
>