Hello, I think you would benefit from reading the series of articles on the subject of LSA types I wrote on our blog. Also, watching "OSPF Area Types" vLecture available from http://bit.ly/vLecture.
-- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Tue, Feb 1, 2011 at 14:51, Vitkovsky, Adam <[email protected]> wrote: > Hi, > > > > I was just wandering whether there are some special cases where Type-4 ASBR > summary LSAs are needed –and if they are needed at all? > > > > Fact is Type-4 LSAs are only advertised by ABRs to all their regular areas > including BB-area (omitting stub-kind of areas) > > > > What I have noticed though is that if the ABR happens to be an ASBR as well > –it won’t advertise itself as ASBR –will not send Type-4 LSA > > > > So I have created a setup with area 0 and area 1 with one ABR between them > and on that ABR I redistributed one of my connected loopbacks > > Routers within area 0 and routers within area 1 only had type-5 lsa with the > external network but no type-4 lsa saying who the ASBR is > > The ping worked as I thought > > > > The point is advertising router id is in Type-5 LSA anyway making it clear > who’s the ASBR > > So why all the ABRs have to mention it redundantly in Type-4 LSA? > > > > > > Adam Vitkovsky CCIP® CCNP® certified > > System Engineer | AT&T Business Solutions - Global Customer Service > > Phone: +421-269-257-375 > > Email: [email protected] > > > > "This message and any attachments to it contain confidential business > information intended solely for the recipients. If you have received this > email in error please do not forward or distribute it to anyone else, but > email me to report the error, and then delete this message from your > system." > > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
