Subject: Re: draft-manral-ospf-router-lsa-unknown-type-02

From: Vishwas Manral <[email-masked]>
Date: Wed, 26 Jan 2005 02:06:47 -0800

Hi Vivek,

> Why does it lead to different databases? 
This leads to the databases being used by the SPF to be different in different routers. I guess those are the exact words you are looking for. I will clarify the text.

>        If the purpose is to make space for extensions, better to 
>        extend LINK-Types once extension is defined.
Unless the text regarding how unknown LSA's are to be treated is clarified such extensions cannot be added.

Thanks,
Vishwas
________________________________________
From: Mailing List [mailto:[email-masked]] On Behalf Of Vivek Dubey
Sent: Wednesday, January 26, 2005 2:09 PM
To: [email-masked]
Subject: draft-manral-ospf-router-lsa-unknown-type-02

Hi Vishwas,

Section 1.
----------
Incase the a Router LSA with an unknown link type is received implementations treat the LSA differently. While some implementations can ignore the link yet process the rest of the LSA others can simply ignore the LSA. This leads to different databases in the routers and hence different routing tables.  

<vivek> Why does it lead to different databases ? 
        Since links were (used/not used) in different implementations, 
        so different routing tables can result. 

        Further what were the reasons that lead to decide in favor of 
        ignoring unknown link type (and process rest of the router  
        lsa) rather than ignoring the router lsa in calculation of 
        routes.

        Were these reasons discussed in previous mail? 

        Morever this draft is allowing presence of information in
        OSPF LSAs ( i.e not Opaque LSAs), that is "unknown" to OSPF.
        If the purpose is to make space for extensions, better to 
        extend LINK-TYPEs once extension is defined. 

        Simpler approach would have been to ignore the Router LSA in
        the calculations and generate a TRAP specifying the error.

Thanks
Vivek