Re: Another requirement [Re: New (-02) version of IPv6 CPE Router draft is available for review]

[Antonio Querubin <tony@lava.net>]

On Thu, 31 Jul 2008, Francois-Xavier Le Bail wrote:

> Another requirement:
>
> The CPE should install a discard (null) or unreachable route for the
> delegated prefix.
>
> Without, a packet to an unused subnet (belonging to the delegated prefix)
> will loop between the CPE (default route to the Edge Router) and the Edge
> Router (route for the delegated prefix to the CPE).
>
> The only difference between the two options is: with unreachable route
> the CPE return ICMPv6 "Destination Unreachable/no route to destination"
> message to the source address instead of only silently discard the packet.

This would definately be a good idea for the first CPE router that gets 
delegated the big block of /56 or /48 (whatever) from the ISP.  But what 
if it's one of the cascaded routers farther downstream?  Some intelligent 
decisions would need to be made by the router - particularly the amount of 
address space to re-sub-delegate (if that's the right term) to downstream 
routers.

Antonio Querubin
whois:  AQ7-ARIN