Re: [DNA] Confirming today's face-to-face meeting decisions

[JinHyeock Choi <jinchoe@gmail.com>]

Sathya

> Yes. The advantage in using a 'Link Identifier' with a scope applicable to all the nodes in the network is that the host will be able to determine whether it is on the same link or not from receiving a single (RA) message. On the other hand, when such identifier is not available, the host can ask the question 'does this landmark still exist' everytime it has (good) reason to believe it may have changed link.
>
> Can we refer to the first scheme as 'link scoped identifier' and second as 'host scoped identifier' scheme? ;-)

Landmark approach don't have to be host scoped. Many hosts can
share the same landmark.

> The question to ask is, whether the cost of establishing the unique link identifier among all the nodes (routers) in the link is worth to avoid an extra 'does this landmark still exists' question and answer?
>
> Link scoped identifier scheme requires completely securing the link so that nobody can spoof a RA message or confuse the link identifier, while we (I am not sure about this) may not need complete security as long as a secure association between the host and the current AR is good in the host scoped identifier approach.

Even with host scoped (?) approach, if there is only the secure
association between a host and the current AR, the host can't securely
detect that a link change has happened. The host can't receive a secure 
message confirming a link change when it actually happens.

JinHyeock