Re: Type-4 LSA and NSSA

Ahhhh... The RFC's! Definitely the best answer to the question! :)

*Scott Morris*, CCIE/x4/ (R&S/ISP-Dial/Security/Service Provider) #4713,

JNCIE-M #153, JNCIS-ER, CISSP, et al.

JNCI-M, JNCI-ER

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Mike Leske wrote:
> Thanks Scott and Narbik for confirming my thoughts.
>
> I think I finally found an "official" confirmation for that.
>
> RFC 1587 The OSPF NSSA Option states on page 5:
> "Type-7 LSAs are only flooded within the NSSA. The flooding of type-7 LSAs
> follow the same rules as the flooding of type 1-4 LSAs."
> But it describes at no point, that Type-4 LSAs will not be flooded into
> NSSAs.
>
>
> However, RFC 3101 The OSPF Not-So-Stubby Area (NSSA) Option, which obsoletes
> RFC 1587, clearly states on page 5:
> "Since Type-5 AS-external-LSAs are not flooded into NSSAs, NSSA border
> routers should not originate Type-4 summary-LSAs into their NSSAs."
>
>
> Cheers
> Mike
>
>
> 2009/5/9 Scott Morris <smorris_at_internetworkexpert.com>
>
>
>> Type 4's are used for next hop reachability to get to the Type 5 LSAs
>> (ASBR). If you have no Type 5's, you have zero need for a Type 4 LSA. :)
>>
>> So I'd suggest that someone messed up in the book?
>>
>> *Scott Morris*, CCIE*x4* (R&S/ISP-Dial/Security/Service Provider) #4713
>>
>
>
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Received on Sat May 09 2009 - 08:35:31 ART