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Re: 答复: Progressing the three inter-domain I-Ds
Hi,
On Jan 16, 2007, at 11:11 PM, ZhangRenhai wrote:
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
In your example, both ASBR1 and ASBR2 are in AS1 ?
would only advertise the optimal route
I guess that you're referring to the BGP route here.
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.
.... This is IP Inter-AS routing ... With the per-domain approach
(inter-AS), BGP can of course be used, thus all necessary information
for ASBR selection is available.
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.
I don't see the scenario you're referring to ...
JP.
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.