Hi, Just read this on CCO:
Note: In IOS release 12.0T and later, RIP does not advertise the default router if the route is not learned via RIP. Therefore, it may be necessary to redistribute the route into RIP, or use the default-information originate command. http://www.cisco.com/en/US/partner/tech/tk365/tk554/technologies_tech_note09186a0080094374.shtml Cheers, Paresh. >>> "Priscilla Oppenheimer" 07/17/03 10:27AM >>> Zsombor Papp wrote: > > At 10:19 PM 7/16/2003 +0000, Priscilla Oppenheimer wrote: > >To be fair, I just checked, and Doyle didn't say anthing about > >redistribution. > > > >The example simply shows configuring > > > >ip route 0.0.0.0 0.0.0.0 192.168.1.82 > > > >The text says that the router that has that config (which is > running RIP by > >the way) advertises the default to other RIP routers. > > > >It goes on to say: > > > >"After a default route is identified in the routing table, > RIP, EIGRP, IGRP > >will automatically advertise it." > > > >That's right, isn't it? > > I don't think so. That's what the original poster questioned > and I agree > with him. If it is right, then I take back everything. RIP does automatically advertise a default route on my routers. Check this out: Albany#show ip route Gateway of last resort is 10.10.0.2 to network 0.0.0.0 10.0.0.0 255.255.255.0 is subnetted, 1 subnets C 10.10.0.0 is directly connected, Ethernet0 172.16.0.0 255.255.255.0 is subnetted, 2 subnets C 172.16.50.0 is directly connected, Ethernet1 C 172.16.20.0 is directly connected, TokenRing0 R* 0.0.0.0 0.0.0.0 [120/1] via 10.10.0.2, 00:00:06, Ethernet0 Albany learned that last route from another router that is configured for RIP on their shared network and has a static route that points to another router. I didn't configure redistribution. But, alas, this didn't work on IGRP or EIGRP. So if anyone has a good errata for Doyle, Volume I, is this in it? Priscilla > > Well, except that about BGP, there I am 100% sure nothing > happens > automatically. :) > > > If it were OSPF you would need redistribution > > And a 'default-info orig' as well. > > Thanks, > > Zsombor > > >, but > >not for those others? > > > >That was the original question. Sorry I confused it with the > statement from > >CertZone, which really meant to cover a different situation. > :-) > > > >Thanks, > > > >Priscilla > > > >John Neiberger wrote: > > > > > > >>>> Zsombor Papp 7/16/03 3:42:18 PM >>> > > > >>I looked at that page in Doyle's book and I thought it's > just > > > a simple > > > >>mistake, or maybe IOS changed since he wrote that, but > after > > > reading > > > this: > > > >> > > > >>>"Handling of default routes varies from protocol to > > > protocol. RIP, IGRP, > > > >>>EIGRP and BGP automatically redistribute default routes > > > while OSPF and > > > >IS-IS > > > >>>require you to explicitly advertise them with the > > > default-information > > > >>>originate statement in your router configuration." > > > >> > > > >>I start to think that these folks (Doyle included) have > some > > > basic problem > > > > > > >>with simple terminology. > > > > > > > >Actually this terminology might not be that simple after > all, > > > as it is not > > > > > > >clear whether something was redistributed unless it is > > > advertised to peers. > > > > > > >So revised statement below. > > > > > > > >Also, I just realized that my above sentence sounds less > > > respectful than I > > > > > > >intended, so I thought I would mention that I learnt a lot > > > from "Routing > > > >TCP/IP" and it's probably the most useful networking book > I've > > > ever read. > > > > > > > >> There is no way "BGP automatically redistributes default > > > routes". > > > >> However it's true that OSPF and ISIS don't advertise the > > > default route > > > >> even if it's redistributed into them, unless > > > 'default-information > > > >> originate' is specified. > > > >> > > > >>So the statement should be something like "RIP, IGRP, > EIGRP > > > and BGP > > > >>automatically advertise default routes that are > redistributed > > > into them, > > > >>while OSPF and ISIS require the 'default-information > > > originate' > > > >>statement." At least I hope that this is a true > statement... > > > :) > > > > > > > >Probably this one is better: > > > > > > > >"RIP, IGRP, EIGRP and BGP automatically accept default > routes > > > that are > > > >redistributed into them, while OSPF and ISIS silently > reject > > > the > > > >redistributed default route unless 'default-information > > > originate' is > > > >configured." > > > > > > > >Thanks, > > > > > > > >Zsombor > > > > > > Actually, I think I wrote that line and it is a little > > > confusing, perhaps. I > > > took great care to be specific with my terminology but it's > > > easy to slip > > > back into bad habits from time to time. Many people use > terms > > > in a haphazard > > > way (like redistribute, advertise, originate, export, > import, > > > accept) > > > without fully considering the implications of using one term > > > over another. > > > With Howard's approval perhaps we should have CZ update that > > > line with your > > > edited version! I like your version better, anyway. :-) > > > > > > Thanks, > > > John Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=72448&t=72211 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
