Manish, RID is *not* an IP address - it's only a 32bit number that looks like an IP address.
-- Marko Milivojevic - CCIE #18427 (SP R&S) Senior CCIE Instructor - IPexpert On Thu, Aug 16, 2012 at 5:49 PM, MANISH <[email protected]> wrote: > Excellent post Marko > > understood now ......huh!!!!!!!! took some time to digest after some > experimentation > > the Key point here is RID of ASBR may *not be a routable ip add*, or if a > routable ip add may not be advertised in ospf via network command > and hence when external routes travels to other areas the advertising > router is still ASBR RID and other areas dont know how to reach that RID > but ABR knows about the RID of ASBR via TYPE 1 LSA > > CONCLUSION: > if the RID is Non Routable IP Add NO LSA Type 4 is needed basically > if the RID is a Routable ip add it will be known to other areas via Type 3 > LSA and Type 4 both > > Thanks all.......for helping out > > GoodLuck !!!! > > > > On Wed, Aug 15, 2012 at 12:49 PM, Marko Milivojevic > <[email protected]>wrote: > >> Manish, >> >> Have you read the series of articles I wrote on OSPF LSA types? >> >> >> http://blog.ipexpert.com/2010/08/11/quick-look-into-ospf-database-router-lsa/ >> >> http://blog.ipexpert.com/2010/09/13/quick-look-into-ospf-database-network-lsa/ >> >> http://blog.ipexpert.com/2010/09/15/quick-look-into-ospf-database-summary-lsa/ >> >> http://blog.ipexpert.com/2010/09/22/quick-look-into-ospf-database-external-and-asbr-summary-lsa/ >> >> http://blog.ipexpert.com/2010/09/27/quick-look-into-ospf-database-nssa-external-lsa/ >> >> There's also a pretty good series written by Joe Astorino on our blog >> that talks specifically about Type 4 LSA: >> >> >> http://blog.ipexpert.com/2009/11/04/ospf-type-4-lsa-the-forward-address-part-1/ >> >> http://blog.ipexpert.com/2009/11/11/ospf-type-4-lsa-the-forward-address-part-2/ >> >> -- >> Marko Milivojevic - CCIE #18427 (SP R&S) >> Senior CCIE Instructor - IPexpert >> >> On Tue, Aug 14, 2012 at 6:40 AM, MANISH <[email protected]> >> wrote: >> > Hi All, >> > >> > can some one please explain me the difference in LSA Type 3 and LSA Type >> 4 >> > >> > as per my understanding >> > >> > LSA Type 3 is used for inter area routes ........meaning all the Type 1/2 >> > inside an area when crosses in to other area will be advertised using >> type >> > 3 >> > >> > LSA Type 4 is the IP address of ASBR. >> > >> > my confusion is if we already know about ip add of ASBR through Type 3 >> > since every thing gets flooded in to other areas why do we need type 4 >> > explicitly to define ip add of ASBR. >> > >> > >> > I read many blogs and other sources but still could not undersdtand. >> > >> > take a look at this blog explanation, will fa0/0 of R6 not be known to >> > other areas using type 3 lsa ? >> > >> > >> http://blog.ipexpert.com/2009/11/04/ospf-type-4-lsa-the-forward-address-part-1/ >> > >> > >> > >> > Thank You. >> > Manish >> > _______________________________________________ >> > For more information regarding industry leading CCIE Lab training, >> please visit www.ipexpert.com >> > >> > Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> > >> > http://onlinestudylist.com/mailman/listinfo/ccie_rs >> > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > Are you a CCNP or CCIE and looking for a job? Check out > www.PlatinumPlacement.com > > http://onlinestudylist.com/mailman/listinfo/ccie_rs _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com http://onlinestudylist.com/mailman/listinfo/ccie_rs
