I suspect OSPF does not modify external admin distance by default b/c it is a link state routing protocol. Every router within the area has the same topology info, so there's no need for AD modification for loop prevention. EIGRP on the other hand still employs "route by rumor", so I can see how having a less preferred external AD would help with loop prevention within the EIGRP domain. AD manipulation helps with loop prevention when routing among several IGP domains but not required within link state area. Please don't take this as gospel, just my thought process. -d
On Fri, Mar 16, 2012 at 10:57 AM, Wilson Tuma <[email protected]> wrote: > > > By default all ospf routes have a default distance of 110. > > But you can use the distance command to change the distance values. (Just > like eigrp does by default). > > > Syntax : > > > distance ospf {[intra-area dist1] [inter-area dist2] [external dist3]} > > > Thanks. > > Wilson F. Tuma > ==================================== > MCSE, MCSA > > Box 1784 Douala > Cell : +237 77 753 753 > Email : [email protected] > ==================================== > > > ________________________________ > From: manjo vj segar <[email protected]> > To: ccie_rs <[email protected]> > Sent: Friday, March 16, 2012 11:50 AM > Subject: [OSL | CCIE_RS] ospf ad 110 > > hi , > got this below question from a fiend. > just taught of sharing it with you guys if anyones intrested in aswering > him. > > > Does anyone know why OSPF does not have an external administrative distance > value? Is there a specific reason for it? Was it just an oversight? > > My question is related to redistribution, as in the issues it causes when > redistributing routes into OSPF and the inefficienceis it causes. > > I understand how to fix these inefficiencies, Route Maps, Change AD value > etc, but I was just wondering if anyone knew the reason why OSPF maintains > the AD of 110 irrespective of whether it's advertising Internal or External > routes . > > regards, > > manoj > _______________________________________________ > 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
