Re: LSA Type 4 again

Hello Molomo ,

can you plz share the output of the show ?

----- Original Message -----
From: "Molomo" <letjedilakopa_at_gmail.com>
To: "Rick Mur" <rmur_at_ipexpert.com>
Cc: <ccielab_at_groupstudy.com>
Sent: Sunday, September 06, 2009 5:50 PM
Subject: Re: LSA Type 4 again

> Rick,
> Actually I did lab it and it was not permitted,
>
> R1---area 1--- R2 ---area 0 --- R3 --area 0--- R4--- area 2--- R5
>
> area 0 backbone
> area 1 normal area
> area 2 is nssa
>
> R5 ASBR
>
> on R1 I cannot see the LSA type 4.
>
> Regards,
> Molomo
>
>
>
> On Sun, Sep 6, 2009 at 4:43 PM, Rick Mur <rmur_at_ipexpert.com> wrote:
>
>> It could be allowed in the NSSA area, but it would have no use.
>> You are correct, the ABR generates a type 4 LSA, when it sees type 5
>> LSA's
>> indeed to describe the location of the ASBR.
>>
>> Try to lab it up. Create a topology, insert some external routes in OSPF
>> and issue a 'show ip ospf database' on a router within the NSSA and see
>> if
>> you have a type-4 in your database. It's always good to see the theory
> being
>> confirmed in a lab, at least that is what helps me to understand and
>> remember the theory.
>>
>>
>> --
>> Regards,
>>
>> Rick Mur
>> CCIE2 #21946 (R&S / Service Provider)
>> Sr. Support Engineer  IPexpert, Inc.
>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>
>>
>> On 6 sep 2009, at 16:27, Molomo wrote:
>>
>> Experts,
>>>
>>> Jeff Doyle says LSA type 4 is allowed in nssa area ( see table below). I
>>> would have thought that since LSA 5 is not permitted then no need to
>>> generate LSA 4.
>>>
>>> My understanding is , ABR generates LSA 4 based on the type 5, to
>>> describe
>>> the position of the ASBR.
>>>
>>>
>>> Or am I missing something here?
>>>
>>>
>>> I have also seen this in Quick Reference Sheet by Anthony Sequeira.
>>>
>>>
>>>
>>>
>>> Table 8-5. LSA types allowed per area type.
>>>
>>> Area Type
>>>
>>> 1&2
>>>
>>> 3
>>>
>>> 4
>>>
>>> 5
>>>
>>> 7
>>>
>>> Backbone (area 0)
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> No
>>>
>>> Non-backbone, non-stub
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> No
>>>
>>> Stub
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> No
>>>
>>> No
>>>
>>> No
>>>
>>> Totally stubby
>>>
>>> Yes
>>>
>>>
> No[*]<mk:@MSITStore:C:\Documents%20and%20Settings\user\Desktop\R&S%20CCIE\Rec
> ommended%20Reading\Books\Cisco%20press\Jeff%20Doyle\CCIE_Professional_Develop
> ment_Routing_TCPIP,_Volume_I,_Second_Edition.chm::/1587052024/ch08lev1sec1.ht
> ml#ch08tn01>
>>>
>>>
>>> No
>>>
>>> No
>>>
>>> No
>>>
>>> Not-so-stubby
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> Yes
>>>
>>> No
>>>
>>> Yes
>>>
>>> [*] Except for a single type 3 LSA per ABR, advertising the default
>>> route
>>>
>>>
>>>
>>> Regards,
>>>
>>> Molomo
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
>>> _______________________________________________________________________
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>
>
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>
>
>
>

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Received on Sun Sep 06 2009 - 23:03:13 ART