Subject: OSPFv3: question about referenced link state type

From: Paul Wells <[email-masked]>
Date: Tue, 5 Nov 2002 17:56:19 -0600

Hello,

I've got a question about the correct values to use in the "referenced
LS type" field of the intra-area prefix LSA.

The OSPFv3 implementations that I'm familiar with set this 16-bit field
to either 0x2001 for a router LSA or 0x2002 for a network LSA.  In each
case the value includes the flooding scope bits, and is the same as
would be found in the "LS type" field of the LSA header of the
referenced LSA.

However, a literal reading of section A.4.9 of RFC 2740 indicates that
the referenced LS type should be 1 or 2.

I'm wondering if other implementors would comment on what they do here,
and whether this is a potential interoperability problem.

Thanks.

- Paul Wells

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From: Yasuhiro Ohara <[email-masked]>
Date: Wed, 6 Nov 2002 09:36:24 +0900

pauwells> However, a literal reading of section A.4.9 of RFC 2740
pauwells> indicates that the referenced LS type should be 1 or 2.
pauwells>
pauwells> I'm wondering if other implementors would comment on what
pauwells> they do here, and whether this is a potential
pauwells> interoperability problem.

Current Zebra ospf6d encodes whole LS-Type including U, S1, S2 bits.
I didn't noticed A.4.9, and just refered LS-Type.

I think it is possible that this becomes an interoperability
problem because A.4.9 specifies the value explicitly.
The interoperability tests I've done so far with some other
implementations did not show me any problem about this, though.

regards,
yasu

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From: Michael J Barnes <[email-masked]>
Date: Wed, 6 Nov 2002 11:31:35 -0800

Paul,

In section 3.4.3.7 there are a number of references that indicate to set
Referenced LS Type to 0x2001 or 0x2002. I think all of the implementations
go by that.

Also, in A.4.9 it doesn't say *to* set the Referenced LS Type to 1 or 2,
it says that if the Referenced LS Type *is* set to 1 then it refers to a
Router LSA, and if it *is* set to 2 then it refers to a Network LSA. This
is a subtle difference, but makes a difference in the interpretation, so
we can say there isn't a conflict.

Regards,
Michael

--
Michael Barnes
Core IP Eng - Routing
408-525-2785

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From: John Cruz <[email-masked]>
Date: Thu, 7 Nov 2002 10:58:27 -0800

We, in Nokia, have also used the "LS type" as defined in Section A.4.2.1
for the value of "Referenced LS Type" for Intra-Area-Prefix LSAs.

John