Sweet, thanks for the info. On Thu, Jun 3, 2010 at 1:36 PM, Tyson Scott <[email protected]> wrote:
> Any time two neighbors are first forming an adjacency and are going thru > the INIT 2-WAY ExStart Exchange Loading Full process; LSA's must be > explicitly acknowledged. > > > > Most of the time explicit acknowledgements are used between neighbors on a > segment. > > > > When the OSPF flooding interval is occurring and a device on a segment > receives a bunch of LSA's it may decide to group all the LSA's together and > send an implicit LSA acknowledgement thru a single LSA Ack instead of > sending an explicit acknowledgement for each LSA. > > > > And the third is it must send an explicit any time it decides not to > forward an LSA either because of an error or better SPF known locally. > > > > This is from RFC 2328 which is the OSPFv2 RFC. Look it up and see if you > can find any more information if you are interested. > > > > If you are looking for more detail then that you are going to have to go to > the writer of the RFC ;). I am not sure of any more detail than above. > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* Joshua Yost [mailto:[email protected]] > *Sent:* Thursday, June 03, 2010 2:23 PM > *To:* Tyson Scott > *Cc:* ccie_rs > *Subject:* Re: [OSL | CCIE_RS] OSPF Acknowledgements > > > > "Decides not to forward the LSA" > > When could this happen? I am thinking that this means like in a DR/BDR > situation where the only routers sending to ALLSPFROUters are the DR and > BDR, so the neighbors need to ackknowledge specifically as they are not > flooding? Does that seem right? > > > On Thu, Jun 3, 2010 at 12:06 PM, Tyson Scott <[email protected]> wrote: > > That is a great question. Doyle is the man so I am going to hope this is > helpful. > > > > Explicit acknowledgements are required anytime the router decides not to > forward the LSA as part of the flooding procedure. > > The article that I found that states this is RFC 5449 on OSPFv3 but I think > the same principle applies > > It is found in Section 5.4.2 Paragraph 3 sub-paragraph 2. > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Joshua Yost > *Sent:* Thursday, June 03, 2010 11:31 AM > *To:* ccie_rs > *Subject:* [OSL | CCIE_RS] OSPF Acknowledgements > > > > When/How are implicit acknowledgements of LSAs done as opposed to Explicit > Acknowledgements? Per Doyle, implicit is we just send a copy of the LSA back > to the originating neighbor in an update. Explicit would be direct or > delayed Link State Acknowledgement. It is explained when direct vs delayed > is used, but not explained when implict vs explicit is used. > > >
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