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:
> There may be problem with precedence if the PD is a /64 and
> there is one
> LAN port that's a /64,
> you'd have to make sure that the null route was lower
> precedence than
> the LAN port otherwise
> you might not have connectivity.  So yes, we do need to
> specify that the
> null route is lower 
> precedence than other routes except for the default route.

Agreed

> -----Original Message-----
> From: Francois-Xavier Le Bail [mailto:fx.lebail@yahoo.com] 
> Sent: Thursday, July 31, 2008 11:33 AM
> To: v6ops@ops.ietf.org; Wes Beebee (wbeebee)
> Subject: RE: Another requirement [Re: New (-02) version of
> IPv6 CPE
> Router draft is available for review]
> 
> --- On Thu, 7/31/08, Wes Beebee (wbeebee)
> <wbeebee@cisco.com> wrote:
> > Agreed.  Perhaps a low precedence route (when all else
> but the default
> 
> > route fails to match) that's a null route would be
> desirable..
> 
> Yes, and with the Good Old "Longest prefix
> match", no problem of
> precedence.
> 
> Francois-Xavier
> 
> > -----Original Message-----
> > From: Francois-Xavier Le Bail
> [mailto:fx.lebail@yahoo.com]
> > Sent: Thursday, July 31, 2008 11:12 AM
> > To: v6ops@ops.ietf.org; Wes Beebee (wbeebee)
> > Subject: RE: Another requirement [Re: New (-02)
> version of
> > IPv6 CPE
> > Router draft is available for review]
> > 
> > --- 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