Re: [DNA] Review of draft-ietf-dna-link-information-03.txt

[Bernard Aboba <bernard_aboba@hotmail.com>]

>I believe the DNAv6 protocol spec says that RS probes occur upon a hint 
>from L2 that the link has changed. The nature of the hint is left as an 
>exercise to the implementor, and may, in fact, be quite different depending 
>on the nature of the L2 protocol. Is that acceptable?

Since it doesn't make sense to send out RS probes on a "Link Down" 
indication, or as the result of events such as rate negotiation, I assume 
that "changed" means "Link Up", no?

>IHO, regardless of what the spec says about the host side, somebody could 
>always hack the driver to flood the link. The DT was primarily concerned 
>with protecting against such attacks, but I suppose it might be appropriate 
>to include some text in the spec to protect against malfunctions as well.

The issue isn't so much DoS (since as you point out, attacks don't have to 
implement the spec), as protecting against malfunctioning drivers.  For 
example, I have seen drivers that don't damp "Link Up" and so it is possible 
to receive ~10 indications per second in some circumstances.   If a number 
of hosts all had the same problem (e.g. if such a malfunctioning driver made 
its way into a mass-market handset), DNA implementations without built-in 
damping could cause serious problems.