Re: LSA Type 4 again

Perfect. Do you see now how it works?

On Sun, Sep 6, 2009 at 2:12 PM, Mohamed El Henawy <m.henawy_at_link.net> wrote:

> i did it
>
> output from R1 when Area 1 is normal area
>
> OSPF Router with ID (10.10.10.10) (Process ID 1)
>
> Summary ASB Link States (Area 0)
>
> Routing Bit Set on this LSA
> LS age: 46
> Options: (No TOS-capability, DC, Upward)
> LS Type: Summary Links(AS Boundary Router)
> Link State ID: 22.22.22.22 (AS Boundary Router address) ===> R3
> Advertising Router: 1.1.1.1
> LS Seq Number: 80000001
> Checksum: 0x6F6F
> Length: 28
> Network Mask: /0
> TOS: 0 Metric: 1
>
> output when Area 1 is NSSA
>
> OSPF Router with ID (10.10.10.10) (Process ID 1)
>
>
>
>
>
> ----- Original Message -----
> *From:* Narbik Kocharians <narbikk_at_gmail.com>
> *To:* Mohamed El Henawy <m.henawy_at_link.net>
> *Cc:* Molomo <letjedilakopa_at_gmail.com> ; Rick Mur <rmur_at_ipexpert.com> ;
> ccielab_at_groupstudy.com
> *Sent:* Monday, September 07, 2009 12:07 AM
> *Subject:* Re: LSA Type 4 again
>
> It will be easy to lab it up.
>
> R1 ------ Area 0 ------ R2 ------ Area 1 ------- R3
>
> Set area 1 to nssa and configure R3 to redistribute a connected interface.
> Then, do a "Show ip ospf da asbr-summ" on R1. Then try it again without
> having Area 1 as NSSA and see the difference.
>
> On Sun, Sep 6, 2009 at 1:03 PM, Mohamed El Henawy <m.henawy_at_link.net>wrote:
>
>> 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/> <
>>>> 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
>>>>>
>>>>> _______________________________________________________________________
>>>>> Subscription information may be found at:
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>>>>>
>>>>
>>>
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>>>
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>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
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>
>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> www.MicronicsTraining.com <http://www.micronicstraining.com/>
> Sr. Technical Instructor
>
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-- 
Narbik Kocharians
CCSI#30832, CCIE# 12410 (R&S, SP, Security)
www.MicronicsTraining.com
Sr. Technical Instructor
Blogs and organic groups at http://www.ccie.net