Subject: Re: draft-ietf-ospf-cap-04.txt

From: Vivek Dubey <[email-masked]>
Date: Tue, 7 Dec 2004 17:34:11 -0000

Peter,

1) In case of ABR analogy, the information was directly relevant to
   OSPF routing and even than it was provided as configuration option, 
   not a "should" condition.

   Here, OSPF RI Opaque LSA is used for both:
   a) Advertising router's OSPF capabilities (TLV 1)
   b) Capablities Opaque to OSPF (Any future TLVs defined)

   And since flooding scope is per TLV and depends on local policy,
   there should be no dependency on Type's of area configured at OSPF 
   level. 

2) 
draft>An OSPF router MAY advertise different capabilities when both
       NSSA/stub area type 10 LSA(s) and an AS scoped type 11 opaque
       LSA is advertised.
vivek> Capabilities here should map to different TLV's ??

Peter>I guess it can be different TLVs or different content in the same TLV.

vivek> Different content in same TLV, advertised in different scoped
       LSAs (Type 10 and Type 11). Doesnt seems a good idea to me.
       Any possible scenarios?

Thanks
Vivek

On Tue, 07 Dec 2004 Peter Psenak wrote :
>Vivek,
>
>Vivek Dubey wrote:
>>Hi,
>>Section 2.3:
>>draft>TLV flooding scope rules will be specified on a per-TLV basis
>>draft>If a type 11 opaque LSA is chosen, the originating router should
>>       also advertise type 10 LSA(s) into any attached NSSA/stub area
>>
>>vivek) If scope of TLV is defined to be AS (Type 11), why should, the
>>       originating router advertise type 10 LSA(s) into any
>>       attached NSSA/stub area ? Idea seems to get the capabilities
>>       advertised to NSSA/STUB neighbors of originating router. But
>>       what about NSSA/STUB areas attached not to "originating"
>>       routers??
>
>an analogy is when you have an ABR connected to backbone area and NSSA
>area and you redistribute routes from some external source. ABR will
>generate Type-5 external LSA, plus it can be configured to advertise
>Type-7 LSA to the NSSA area for the same prefix.
>If you have another ASBR somewhere in backbone area, Type-5 LSAs it
>generates will not get propagated to NSSA area.
>
>>
>>draft>An OSPF router MAY advertise different capabilities when both
>>       NSSA/stub area type 10 LSA(s) and an AS scoped type 11 opaque
>>       LSA is advertised.
>>vivek> Capabilities here should map to different TLV's ??
>
>I guess it can be different TLVs or different content in the same TLV.
>
>Peter
>
>>
>>Thanks
>>Vivek
>>
>>
>>
>><http://clients.rediff.com/signature/track_sig.asp>

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From: Acee Lindem <[email-masked]>
Date: Tue, 7 Dec 2004 17:16:55 -0500

Hi Vivek,

>   not a "should" condition.
I think the configuration option is implementation specific. Although it is
not covered explicitly I think RFC 3103 implies an ABR will redistribute
into both attached NSSAs and regular areas.

>       LSAs (Type 10 and Type 11). Doesnt seems a good idea to me.
JP - can you take a shot at this? I seem to remember that you had a
scenario in minde.

Thanks,
Acee

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From: JP Vasseur <[email-masked]>
Date: Tue, 7 Dec 2004 17:25:18 -0500

Hi Vivek,

> JP - can you take a shot at this? I seem to remember that you had a

Indeed. In the case of TE, there are various cases where a router may
want to advertise a capability with different flooding scopes thus two
different opaque LSAs. For instance, a router may belong to two
different meshes of TE LSPs, one local to its area (RI LSA of Type 10)
one across the routing domain (RI LSA of Type 11). The same TLV
(automesh) is used, with different contents, carried in different LSA
(type 10 and 11).

Thanks.

JP.