Hi Benny, I just labbed this up as well to see if I saw the same, and I do. And the more I think about it, the more sense it makes.
This is normal behavior because of the nature of 10.1.23.0/24 on R2. Remember that your 10.1.23.0 network is actually seen on R2 as Connected, not an OSPF or RIP route. So RIP is seeing that connected route, for which it has a matching network statement and thus it is importing it into RIP. Since that interface does not participate in EIGRP, there is no EIGRP internal route for 10.1.23.0. RIP has a route for 10.1.23.0, due to being active on that interface, and that route is outside of the EIGRP domain, so EIGRP imports it as a D EX based on the redistribution config. There's no way you can, on one router, redistribute from OSPF to RIP and then RIP to EIGRP. A router will not redistribute routes a second time. (I'm sure Marko will correct me with some crazy was to make that happen...). You can prove this by advertising a route from R3 into OSPF. R2 will learn it as an intra-area OSPF route but RIP will not see it and thus R4 will never get it. I also just disabled RIP on my example and redistributed OSPF directly into EIGRP, and I see the same effect. 10.1.23.0/24 is in R4 as a D EX, because that interface is a "native" OSPF route and we're redistributing OSPF into EIGRP. Also note that if you had activated RIP for some other classful network ( 192.168.1.0/24, for example) and redistributed connected into RIP, you would not see the 10.1.23.0 prefix land in EIGRP, again due to the one-redistribution-per-router rule. Hope that helps, Bob On Wed, Mar 7, 2012 at 10:02 AM, Benny Sumardy <[email protected]> wrote: > > Hi, > > I am doing a redistribution lab. There's a router R2 running RIP, OSPF and > EIGRP100, with redist OSPF-to-RIP and redist RIP-to-EIGRP100. R2 interface > Fa0/0.23 (10.1.23.0/24) is participating on RIP and OSPF. > > R4 is running EIGRP100 and form adjancency with R2. And when i run show ip > route eigrp 100 on R4, i am seeing the route 10.1.23.0/24 as "D EX" route > indicating that this route was redistributed from RIP. > > The question is, why 10.1.23.0/24 was part of RIP routes? I was under > impression that if RIP and OSPF co-exist, OSPF should win the right (better > metric than RIP) to install the 10.1.23.0/24 route onto the routing > table, and routing table will cease the RIP route. Yet, when on R4 routing > table, the 10.1.23.0/24 is still exist on RIP table. > > Thanks in advance for the assistance. > > Brgds > Benny > > _______________________________________________ > 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
