Subject: OSPF-V3 Instance ID

From: Dilip Kumar <[email-masked]>
Date: Thu, 8 Jul 2004 19:37:24 -0700

Hello,
    I have couple of doubts w.r.to OSPF-V3's Instance ID interpretation
1. Can one router interface have more than one "Instance ID"
configured simultaneously ?
OSPF-V3 MIB draft (draft-ietf-ospf-ospfv3-mib-08) indicates that it is
not possible. However, RFC-2740 indirectly points that it is possible.
Following is the excerpt from the RFC-2740

  "Another use for running multiple OSPF instances is if you want, for
   one reason or another, to have a single link belong to two or more
   OSPF areas."

2. Can LSAs received from a neighbor 'A' which has instance ID=2 be
flooded to another neighbor B that has instance ID=5 ?

       InstanceID=2                  InstanceID=5
A=================R================B

Thanks in advance for any help.
-- Dilip

---

From: Acee Lindem <[email-masked]>
Date: Thu, 8 Jul 2004 23:15:01 -0400

Hi Dilip,

----- Original Message -----
From: "Dilip Kumar" <[email-masked]>
To: <[email-masked]>
Sent: Thursday, July 08, 2004 10:37 PM
Subject: OSPF-V3 Instance ID

> configured simultaneously ?

Yes.  However,  there may be implementations that only support one to
be configured.

> not possible.

This is wrong. ospfv3IfTable should be indexed by both ospfv3IfIndex
and ospfv3InstId.

> However, RFC-2740 indirectly points that it is possible.

This is one application of multiple instance IDs.

> A=================R================B

The base OSPFv3 specification (RFC 2740) certainly doesn't preclude this
since the interface instance ID only has significance for that interface.
In case of draft-mirtorabi-ospf-multi-area-adj-00.txt, the instance ID has
significance beyond the scope of the interface and you would not.

Hope this helps,
Acee