Query on RFC1793 (OSPF over demain circuits)

Paresh Khatri <Paresh.Khatri@AAPT.COM.AU> Fri, 08 July 2005 10:49 UTC

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From: Paresh Khatri <Paresh.Khatri@AAPT.COM.AU>
Subject: Query on RFC1793 (OSPF over demain circuits)
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Hi all,

I'm trying to understand the example in Section 2.5 - Interoperability with unmodified OSPF routers.  

The example states that router B (a non-DC capable router) will treat DoNotAge LSAs as MaxAge LSAs and will acknowledge them as such to router A.  But router A will notice that the ack is for a different instance and will re-transmit the LSA.  My question is - why would router A consider it to be an ack for a different instance ?  Is the implication here that router B would set the Age in the LSAck to be MaxAge and not the Age that was present in the received LSA ?

Thanks in advance.


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