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Re: Proposed strategy for Inter-area/AS
Hi,
Thanks for clarifying. See below...
> Requirement drafts clearly point out that routing (IGP, EGP)
> extensions should be avoided, except some minor extensions to
> advertise static parameters such as PCS capabilities for instance
> (addressed in point 5).
I am not sure that I can find any text in the two TEWG drafts
that actually says what you suggest.
In the inter-area requirement draft, we clearly point out that
information propagation for path-selection should continue to be
localized and that leaking of TE link information across areas MUST be
precluded (section 5.3.1).
Note that this includes any summarized/aggregated TE link information.
I agree that this is not clear in current version, we will clarify in
next revision.
How right you are :-)
The draft currently says...
The solution MUST entirely preserve the concept of IGP hierarchy. In
other words, flooding of TE link information across areas MUST be
precluded.
I took "flooding" to be a more free distibution of information that
"leaking".
For example, I would consider that the Summary LSA is "leaking" routing
information from one LSA to another, but it is not flooding that
information.
If you are saying that ABSOLUTELY NO TE information may be exchanged
between areas, then I wonder how an ingress LSR can know the reachability
to the egress (let alone the availability of suitable paths) when areas have
more than one ABR. (Note that TE addresses are not necessarily routable!)
I would have a problem with the requirements draft if it is precluding ALL
exchange of TE information between areas. A more appropriate requirement
would describe scalability and impact on existing operation of routing
protocols, but would not constrain the solution in this way.
. . . . .
Can you tell me the status of this draft? Is it still alive in the TEWG?
Is TEWG working on it? When is it scheduled to be completed?
Thanks,
Adrian