Alex,

I think LSA ack applies to flooding procedure. During LSDB sync, one will
keep sending the request until it receives the LSA update. When receiving
the request, the other end will just sent out the LSA update without
expecting the ack. This way, the two routers will have the same LSDB.

Thanks,

Yu

> -----Original Message-----
> From: Alex Zinin [mailto:azininNEXSI.COM]
> Sent: Wednesday, October 24, 2001 2:43 AM
> To: OSPFDISCUSS.MICROSOFT.COM
> Subject: Re: Acknowledgement for Router LSA from DROther.
>
>
> Folks,
>
> To answer the original question---the DR should not
> explicitly ack the LSA received from a non-DR router,
> as it will flood the LSA back to the interface to
> AllSPFRouters, so the router that sent the LSA will treat
> this update as an implied ack.
>
> As for Feng's point 2 below, the statement is not correct.
> You have to ack LSAs during the LSDB exchange process according
> to normal rules, there's no special case for the Exchange process.
> This question has been explained lately on the list, pls see
> the archives.
>
> --
> Alex Zinin
>
> Monday, October 22, 2001, 3:01:41 PM, Xie, Feng wrote:
>
> > Hi, Gurpreet:
>
> > I think there could be two cases in which no explict
> acknowledgments
> > are needed:
> > 1. The case described by section 13, 7(a);
> > 2. In DB sync in which router A sends a request to
> router C. When
> > router C responds to this request with some link state
> update, router A may
> > send the next request or do nothing if there is no further
> request. Refer to
> > RFC2328, p105. My understanding is that in this case, the
> next request or no
> > request may serve as an implicit ack because if the update
> is not received
> > by router A, it will resend its request again.
>
> > Feng Xie
>
> > -----Original Message-----
> > From: Singh, Gurpreet [mailto:Gurpreet.SinghSPIRENTCOM.COM]
> > Sent: Monday, October 22, 2001 5:48 PM
> > To: OSPFDISCUSS.MICROSOFT.COM
> > Subject: Re: Acknowledgement for Router LSA from DROther.
>
>
> > Hi Xie
>
> > However,
> > acknowledgments can also be accomplished implicitly
> by sending
> > Link State Update packets (see step 7a of Section 13)."
>
> > Does this mean that implied acknowledgement is done only in
> the case of 7a
> > of section 13 ?
> > Section 7a is valid only for LSAs for which the router has
> the same instance
> > in the database as the received LSA.
>
>
> > Gurpreet
>
> > -----Original Message-----
> > From: Xie, Feng [mailto:Feng.XieMARCONI.COM]
> > Sent: Monday, October 22, 2001 5:36 PM
> > To: OSPFDISCUSS.MICROSOFT.COM
> > Subject: Re: Acknowledgement for Router LSA from DROther.
>
>
> > Hi, Gurpreet:
>
> > According to RFC2328, p152,
>
> > "Each newly received LSA must be acknowledged. This is usually
> > done by sending Link State Acknowledgment packets. However,
> > acknowledgments can also be accomplished implicitly
> by sending
> > Link State Update packets (see step 7a of Section 13)."
>
> > Base on the above statement, my understanding is that A
> may not need to
> > send an explicit link acknowledgment for every router lsa
> it receives from C
> > if the router lsa is received during DB sync.
>
> > Feng Xie
>
>
> > -----Original Message-----
> > From: Singh, Gurpreet [mailto:Gurpreet.SinghSPIRENTCOM.COM]
> > Sent: Monday, October 22, 2001 5:27 PM
> > To: OSPFDISCUSS.MICROSOFT.COM
> > Subject: Acknowledgement for Router LSA from DROther.
>
>
> > Hi
>
> > If there are three routers on the same sub-net A (DR) ,
> B (Backup DR)
> > and C (DR Other). Should A acknowledge a router LSA (which
> A does not have a
> > copy in the database) received from C ? i.e. should router
> LSA from a
> > DROther be acknowledged by the DR (Designated Router)
>
>
> > Thanks
>
> > Gurpreet
>

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]