答复: Progressing the three inter-domain I-Ds

[ZhangRenhai <zhangrenhai@huawei.com>]

> > After reading these docs I also have the same concern with you
> > about inter-ASBR links flooding.
> > I think, in oder to perform  inter-AS path computation, inter-ASBR
> > links fooding is desired.
> 
> As pointed out in the document, this is not a MUST, but an optimization.
> 
> > But
> > such kind of inter-ASBR link info should include more information
> > than "normal" TE links do,
> > e.g: the inter-ASBR links info SHOULD still include the peer AS
> > number and peer ASBR router id
> > besides those link info which has been specified in rfc3630 and
> > rfc3784.
> 
> I don't think that the peer AS number info should be included in the
> IGP for sure. You should rely on BGP for that purpose.
[ZhangRenhai>] maybe BGP is not enough for some circumstance, take this
scenario for example:
                    
                     /  ASBR4
ASBR1--------ASBR2--
                    \  ASBR3
------AS 1----------||-----AS 2----------

ASBR2 in AS 1 would only advertise the optimal route received respectively
from ASBR3 and ASBR4 (both are from AS 2) to ASBR1, ASBR1 also doesn't have
the full knowledge of topology(such as which AS the ASBR2 is connected to
and which router is in that AS)between the two AS. PCE would have the
similar problem when performing the brpc.
Another issue, when ASBR1 receives a path mesg from upstream domain
containing a loose ERO:AS number(say AS2), there should be a method for it
to locate the asbr(say ASBR2) in the local domain connected to AS2. 

Regards,
Zhang Renhai

>  
> >
> > So I think there need a document to clarify and specify inter-ASBR
> > links flooding. we are considering to
> > write such a document. If someone interested in such work, we could
> > cooperate.
> >
> 
> JP.
> 
> >