Re: Clarification on Flooding

[Parag Deshpande <[e-mail]>]

From my understanding this is what it means -
A router requests an lsa when either the lsa is not present in its db or the
db copy is older.
When router receives a DD packet that contains a new/newer lsa it would
request that lsa from the nbr.

In this case the nbr sent an lsa which is either same or older which either
means that the request
created was incorrect or the nbr misbehaved, hence the Database exchange
must restart.

Parag


----- Original Message -----
From: Paresh Khatri <[e-mail]>
To: <[e-mail]>
Sent: Wednesday, June 11, 2003 5:55 PM
Subject: Clarification on Flooding


HI all,

Would someone be able to explain the following clause in RFC2328 to me ?

This is in Section 13. Flooding Procedure:

    Page 145
    (6) Else, if there is an instance of the LSA on the sending
        neighbor's Link state request list, an error has occurred in the
        Database Exchange process.  In this case, restart the Database
        Exchange process by generating the neighbor event BadLSReq for
        the sending neighbor and stop processing the Link State Update
        packet.

Why is this an error ?  If the LSA is on the Link state request list for the
neighbor, are we not expecting that
LSA from that neighbor ?

All responses appreciated.
Paresh Khatri.