Re: [DNA-BOF] Detecting Network Attachment BoF description (rev 2)

[Thomas Narten <narten@us.ibm.com>]

Alper Yegin <alper@docomolabs-usa.com> writes:

> > I see mobility/movement as basically disconnection from one
> > subnet and connection to another.

> I think we need to differentiate between link/subnet/prefix changes.

> For example, host might change its access point (L2 bridge) but it may stay
> connected to the same access router. In this case, there is no change
> required in the IP state.

And indeed, I'm in the camp that assumes that APs are L2 things below
IP, so of an AP changes, that is invisible to IP. If the new AP were
on a different link, that would imply a disconnect/reconnect from one
link to another. That is visible to IP (but only after L2 has done its
work and decided so). But I assume that many interactions with AP are
not visible to IP.

> Or, host might change its access point and consequently access router, but
> the two routers might be advertising the same prefix. In that case, IP
> address of the host does not change, but default router information must
> change. So, even if the subnet does not change, host has to react to
> this.

Does it? I assume that the AR is the default router on the link. If
the AP changes, but the AR does not, why is this visible to IP? It
doesn't need to be.

Thomas