Re: WPD-6, WAA-8, and WAA-9 of draft-ietf-v6ops-ipv6-cpe-router-04

[Ole Troan <ot@cisco.com>]

On Apr 7, 2010, at 9:19 , Philip Homburg wrote:

In your letter dated Tue, 6 Apr 2010 19:57:44 +0200 you wrote:

Suppose we have a packet with source S, and destination D. At =

Ethernet0 with

address I we discover that we cannot forward the packet anymore. So we

generate an ICMP with source I and destination S and use Ethernet0's =

default

router (probably internal to the node because we a talking about a =

router) to

send the packet on its way to S.

=20

Whether destination D is at Serial0 or not is irrelant.

me thinks you are confused...

Yes, I am completely confused about the point you are trying to make.

But I have more enough experience with IPv4 and IPv6 strict multi-homing
implementations to know how they behave in practice.

So maybe you can give enough details about your scenario to make it possible
for someone else to verify whether strict multi-homing will fail in the
way you say it will or not.

what is "strict multi-homing"?

in the following figure from the draft:

                             |                             /

                             | Customer                   /

                             | Internet connection       /

                          Wi |

                      +------+--------+                  \

                      |     IPv6      |                   \

                      | Customer Edge |                    \

                      |    Router     |                    /

                      +---+-------+-+-+                   /

          Network A       |       |   Network B          | End-User

    ---+-------------+----+-    --+--+-------------+---  |network(s)

       |             |               |             |      \

   +----+-----+ +-----+----+     +----+-----+ +-----+----+  \

   |IPv6 Host | |IPv6 Host |     | IPv6 Host| |IPv6 Host |  /

   |          | |          |     |          | |          | /

   +----------+ +-----+----+     +----------+ +----------+/

you have a source S on the Internet sending to a destination D on Network A. D does not exist on network A. you previously said you wanted an ICMP error to use a source address giving most information about where the problem occurred, i.e the IPv6 CE router's address on the interface to network A.

the ICMP error message will be sent back to S through interface Wi.

the strong host model will require that the ICMP message is sent with an address from Wi.

the weak host model allows the use of a source address from the interface connected to network A.

/ot