Re: Comments on draft-yourtchenko-colitti-nd-reduce-multicast

[Ole Troan <[e-mail]>]

Hemant,

we are severely digressing here, but since it is Friday...

> The RA has the A-bit set and the L-bit cleared.  So as per the specification text above the L-bit is zero and the host does not get any on/off--link determination from the L-bit for the addresses covered by the prefix in the PIO.   The host configures its ipv6 address from the PIO in the RA using SLAAC.  Now the host has to send a packet out an interface and the packet destination in the host's Neighbor Cache.  The packet destination also matches the host's prefix to a /64.  So what does the host do?  
> 
> Issue 
> 
> (a) an address resolution NS (assuming the destination is on-link) due to SLAAC operation.
> 
> or
> 
> (b) send the packet to the default router(s).  The L-bit has conveyed no on- or off-link information.  So doesn't the host resort to (a) above.  If the host choses to go to operation (b) what signaled to the host that the destination is off-link?   If the host picked (a), why is that?
> 
> If you can't determine one concrete choice from the two above, we have an ambiguity. 

there is no ambiguity. see the conceptual sending algorithm in section 5.2, RFC4861.
a prefix with the L flag = 0 is not added to the Prefix List. if the Prefix List is empty all packets will be sent to the default router, apart from packets destined to fe80::/10.

cheers,
Ole