Re: OSPF-V3 Instance ID

Acee Lindem <acee@REDBACK.COM> Fri, 09 July 2004 03:15 UTC

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Date: Thu, 08 Jul 2004 23:15:01 -0400
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From: Acee Lindem <acee@REDBACK.COM>
Subject: Re: OSPF-V3 Instance ID
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Hi Dilip,

----- Original Message -----
From: "Dilip Kumar" <dilipks@GMAIL.COM>
To: <OSPF@PEACH.EASE.LSOFT.COM>
Sent: Thursday, July 08, 2004 10:37 PM
Subject: OSPF-V3 Instance ID

> 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 ?

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

> OSPF-V3 MIB draft (draft-ietf-ospf-ospfv3-mib-08) indicates that it is
> not possible.

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

> 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."

This is one application of multiple instance IDs.

>
> 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

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

>
>
> Thanks in advance for any help.
> -- Dilip