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

["Wes Beebee (wbeebee)" <wbeebee@cisco.com>]

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.

- Wes

-----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