Re: NSSA and Totally NSSA

Defining a Not-So-Stubby Area

In order to make a stub area into an NSSA, issue this command under the OSPF
configuration:

router ospf 1
 *Area 1 nssa*

This command must be configured on every single router in Area 1. After you
define Area 1 as an NSSA, it must have these characteristics:

   -

   No Type 5 LSAs are allowed in Area 1. This means no RIP routes are
   allowed in Area 1.
   -

   All IGRP routes are redistributed as type 7. This type 7 can only exist
   within NSSA.
   -

   All type 7 LSAs are translated into type 5 LSAs by the NSSA ABR and are
   leaked into the OSPF domain as type 5 LSAs.

Defining an NSSA Totally Stub Area

In order to configure an NSSA totally stub area, issue this command under
the OSPF configuration:

router ospf 1
 *Area 1 nssa no-summary*

Configure this command on NSSA ABRs only. After you define the NSSA totally
stub area, Area 1 has these characteristics in addition to the NSSA
characteristics:

   -

   No type 3 or 4 summary LSAs are allowed in Area 1. This means no
   inter-area routes are allowed in Area 1.
   -

   A default route is injected into the NSSA totally stub area as a type 3
   summary LSA.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094a88.shtml#definenotstub
 --
Garry L. Baker

"There is no 'patch' for stupidity." - www.sqlsecurity.com
"Complexity is the enemy of reliability..."

On Fri, Mar 18, 2011 at 3:39 PM, Clark, Neil <Neil.Clark_at_atosorigin.com>wrote:

> Hi Guys,
>
> I think I am being a divvy I am struggling to see the main difference
> between NSSA and Totally NSSA. Could someone point out the key
> differences for me?
>
> Thanks
>
> Neil
>
>
>
>
>
>
>
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Received on Fri Mar 18 2011 - 16:04:01 ART