( it's Marko - no "c" :-) ) Since you are not allowed to use priority command, but you need to ensure that certain router MUST be DR, you need to remember that you can only so much influence OSPF here. If DR is elected, nothing with displace it. So, unless you are allowed to use priority, there is no way to ensure 100% election.
So, what I would do here is to make sure that spokes have their interfaces in shutdown. I would change router-id on hub router to be higher than any of the spokes and ensure that hub interface is up and running. Once it's up and running and DR is elected, only then I would enable spokes. I believe this is the approach taken in the DSG... This is just a little bit misleading, though :-). When routers reload, there is really no way to ensure that hub will become DR, but if that's not a requirement, there is nothing else you can do here. -- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert Mailto: [email protected] Telephone: +1.810.326.1444 Fax: +1.810.454.0130 R&S Video on Demand Demo: http://bit.ly/aFyrU4 On Sun, Mar 7, 2010 at 17:23, RAragon <[email protected]> wrote: > ===From D.J. Marcko=== > Hi, > > No, this is not an acceptable solution. Router that will get elected > DR will originate type 2 LSA and this will not be interpreted properly > by nodes that don't expect type 2 for their point-to-point link. There > will be "oddities" in your OSPF database and RIB after configuring > this, where LSAs will be present in the database, but routes not > inserted in the RIB. > > These would be lost points on the exam. All routers *must* agree > whether there is DR or not on the common segment. The proper solution > is to modify priority on R5 and R6 to prevent them becoming DR. What > value should you use here? > > -- > Marko Milivojevic - CCIE #18427 > Senior Technical Instructor - IPexpert > > Mailto: [email protected] > Telephone: +1.810.326.1444 > Fax: +1.810.454.0130 > R&S Video on Demand Demo: http://bit.ly/aFyrU4 > - Show quoted text - > > > Marko, > Great point. Geeze I should have thought that through a little more. > > The questions says " No routers on the link are allowed to use the > "priority" command. > > However, if it allowed me to use it I would have used Priority 0 which > basically says "never become DR/BDR" for that segment/link. > > > Thanks, > > Ray > > _______________________________________________ > 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
