Well logically you'd have problems with the 2nd condition regardless of IOS restrictions. To use a few situations to describe why is probably easier to follow the 2nd condition.
Some OSPF Network--Router A(device under consideration)---Router B 1) RouterA received default via OSPF and passes it on. You've got this router with a default learned via the upstream(lefthand) OSPF network. It can and will pass that default on to other OSPF routers such as RouterB. You've gotten what you'd hoped for, right? And by coincidence the 2nd condition the SE described is met. Exceptions are when you want RouterB to always point default to RouterA, even when it becomes disconnected from the rest of the OSPF network. Some OSPF Network---RouterC---RouterA---RouterB 2)RouterA learns default via OSPF network and originates a new default Again RouterA learns default in the same manner. But this time RouterA is configured to insert(originate) a default route into the OSPF domain. RouterA now injects this default and sends to neighbors. Neighboring routers such as RouterC now have a better path to default through RouterA and drop the default received from the rest of the OSPF network. As a result RouterA looses the default it was using in forwarding, but is receiving traffic it now can't forward. Of course if RouterA is NOT configured for default originate always then it will drop the default annoucement and things will cycle endlessly. I take it this isn't what you'd want, right? ;-) 3)Now maybe your entire network is just Router's A,B,andC. Then RouterC would have a default learned from somewhere else and hopefully a lower admin distance than the default seen from RouterA. Then you could have a survivable situation where RouterA can originate a new default based upon RouterA. It would look strange on some levels but it would function. I would say that for #2 or 3 that you'd be better off pointing default with a static route on RouterB than trying to get OSPF to do that. Same would go for strict primary/secondary default paths with two circuits out of RouterB. If you describe the intended situation in more detail, folks here could probably give better input. Regardless I hope these examples help clear things up. Good Luck, Darrell http://www.hayaitacos.net/mpeer/ ""John Neiberger"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > You'll have trouble finding documentation for the second condition > because it's baloney. :-) > > Of course, if I'm wrong or if there is some odd twist to this that I'm > not familiar with, someone will correct me. > > Regards, > John > > >>> "Hart, Todd A [LTD]" 1/23/03 9:44:09 > AM >>> > I would like to know if anyone knows where I can find documentation > regarding criteria for OSPF to originate default using the > default-information originate command? Our Cisco SE provided me with > the > following information, and he is trying to locate information to > support the > second condition of, "- That default route *cannot* have been learned > via > OSPF." > > In order for 'default-information originate' to redistribute a default > route, 2 conditions must be met: > - The router must have a default in it's routing table > - That default route *cannot* have been learned via OSPF > > I have found Cisco supporting documentation regarding the first > condition, > but not the second. I would appreciate any documentation regarding > this > issue. > > Thanks, > Todd Hart Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=61696&t=61683 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
