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

[Francois-Xavier Le Bail <fx.lebail@yahoo.com>]

--- On Thu, 7/31/08, Wes Beebee (wbeebee) <wbeebee@cisco.com> wrote:
> The route should go to the LAN ports (for the delegate
> prefix).  If the LAN ports happen to not be up, doesn't this 
> cause the packet to be > dropped?  If the destination matches a 
> loopback, then the packets can be
> serviced by the loopback.  If there is no LAN port (# of
> LAN ports = 0),
> and if the device still does DHCPv6 PD (for other
> addresses), then a
> null route may be appropriate as long as the other
> addresses get
> serviced at a higher priority.

For example, if the delegated prefix is a /56 and the CPE use
a /64 prefix for a subnet on a LAN Bridge and another /64 for a
subnet on another LAN interface outside the bridge,
there are many prefix/subnet not used.

Packet to theses unused prefix/subnet will loop without a discard 
or unreachable route.

Francois-Xavier

> -----Original Message-----
> From: owner-v6ops@ops.ietf.org
> [mailto:owner-v6ops@ops.ietf.org] On
> Behalf Of Francois-Xavier Le Bail
> Sent: Thursday, July 31, 2008 10:17 AM
> To: v6ops@ops.ietf.org
> Subject: Another requirement [Re: New (-02) version of IPv6
> CPE Router
> draft is available for review]
> 
> 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.
> 
> Francois-Xavier