I believe so Ajay. Matthew R Thomas 07940 585456 ________________________________
From: ajay thakur [mailto:[EMAIL PROTECTED] Sent: Tue 04/09/2007 17:30 To: Matthew Thomas Cc: [email protected] Subject: Re: [OSPF] duplcate entries in retransmission list ? You mean to say whenever we add LSA in retransmission list we should remove old LSA & add new LSA in the list. ? Thanks Ajay Matthew Thomas <[EMAIL PROTECTED]> wrote: Hi Ajay, I believe these conditions have been selected to make sure this doesnt happen: (excerpt from 2328) 13.1. Determining which LSA is newer When a router encounters two instances of an LSA, it must determine which is more recent. This occurred above when comparing a received LSA to its database copy. This comparison must also be done during the Database Exchange procedure which occurs during adjacency bring-up. An LSA is identified by its LS type, Link State ID and Advertising Router. For two instances of the same LSA, the LS sequence number, LS age, and LS checksum fields are used to determine which instance is more recent: o The LSA having the newer LS sequence number is more recent. See Section 12.1.6 for an explanation of the LS sequence number space. If both instances have the same LS sequence number, then: o If the two instances have different LS checksums, then the instance having the larger LS checksum (when considered as a 16-bit unsigned integer) is considered more recent. o Else, if only one of the instances has its LS age field set to MaxAge, the instance of age MaxAge is considered to be more recent. o Else, if the LS age fields of the two instances differ by more than MaxAgeDiff, the instance having the smaller (younger) LS age is considered to be more recent. o Else, the two instances are considered to be identical. Matthew R Thomas 07940 585456 ----- Original Message ----- From: ajay thakur <mailto:[EMAIL PROTECTED]> To: [email protected] Sent: Tuesday, September 04, 2007 3:35 PM Subject: [OSPF] duplcate entries in retransmission list ? HI all, Is it possible that router tries to add same LSA entry in the neighbor retransmission list multiple times? Given the fact that only {adv-rtr, LS-Id, lsa-type} are used to identify LSA. What is {adv-rtr,ls-id,lsa-type} is same for both the routers but ls-seq, age, checksum different for both the lsa? Can somebody clear my doubt. Thanks Ajay ________________________________ Once upon a time there was 1 GB storage in your inbox. Click here for happy ending. <http://in.rd.yahoo.com/tagline_mail_3/*http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/> ________________________________ _______________________________________________ OSPF mailing list [email protected] https://www1.ietf.org/mailman/listinfo/ospf ________________________________ 5, 50, 500, 5000 - Store N number of mails in your inbox. Click here. <http://in.rd.yahoo.com/tagline_mail_4/*http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/> _______________________________________________ OSPF mailing list [email protected] https://www1.ietf.org/mailman/listinfo/ospf
