Re: draft-bagnulo-pshim6-01.txt

[marcelo bagnulo braun <[e-mail]>]

El 13/05/2007, a las 20:23, Deguang Le escribió:

> marcelo bagnulo braun schrieb:
>
>> Hi Deguang,
>> El 13/05/2007, a las 17:37, Deguang Le escribió:
>>> Dear Prof. Marcelo,
>>> page5:
>>>  When H1 sends the first packet addressed to the CMULA of H2, the
>>>    packet is intercepted and processed by the P- Shim6 box of the
>>>    multihomed site.
>>>
>>> As above description, H1 sends the first packet, which uses the 
>>> CMULA of H2 as the destination address. The CMULA is site-local 
>>> adddress.
>>>
>> right
>>> Since the destination addresss of the first packet is the CMULA of 
>>> H2 that belongs to H2's site, I wonder if this packet can be routed 
>>> in H1's site.
>>>
>> this packet is routed to the P-shim box in the H1 site. the P-Shim6 
>> box of the H1 site will then establish the shim6 context whcih will 
>> have the CMULAs as ULIDs and regular PA addresses as locators. After 
>> that it will forward the packets outside H1 site towards H2 site 
>> containing the PA addresses as locators.
>> So the packets will carry PA addresses in the IPv6 header once they 
>> leave the site. CMULAs are only routed inside the local site, so this 
>> would be compliant with proposed usage of ULAs.
>> does this address your point?
> Thank you very much for your detailed explaination. :-)
> As you said, through the path from H1 to P-shim, the destination 
> address of this packet is the CMULA of H2, which however is not 
> routable in the H1's site (the reasions have been listed below). 
> Normally, the CMULA of H2 can only be routable in the H2's site since 
> it belongs to site-local address. right?
>

right i see your point now.

the idea is that the P-shim box will inject a route to the CMULA 
prefix, sinking all packets addressed to CMULA prefix (other than the 
local CMULA prefix)

then P-shim6 box would replace the CMULA to a globally routable PA 
address. So the CMULAs would be  routed inside the sites and PA address 
will be routed in the interdomain

that makes sense?

Regards, marcelo


> Therefore, I only wonder how this packet could be routed from H1 to 
> P-shim box correctly.
>
> With best regards,
> Deguang
>
>
>
>> Regards, marcelo
>>> The reasions are ss follows:
>>> According to rfc2373, routers must not forward any packets with 
>>> site-local source or destination addresses outside of the site.
>>>
>>> Reference [12] has the following description:
>>> Unique Local IPv6 Unicast Addresses are intended for local 
>>> communications, usually inside of a site.
>>>
>>> RFC4193 provides operational guidelines that forbid default routing 
>>> of local addresses between sites in section 4.1.
>>>
>>> By the way, the reference [12] seems have been updated by RFC 4193.
>>>    [12]  Hinden, R. and B. Haberman, "Centrally Assigned Unique Local
>>>          IPv6 Unicast Addresses", draft-ietf-ipv6-ula-central-01 
>>> (work
>>>          in progress), February 2005.
>>>
>>> Cheers,
>>> Deguang
>>>
>