While I see what you are saying. EIGRP is still advertised as a flat routing protocol by Cisco, while OSPF is advertised as being an "area-based hierarchical system" with features found in that type of protocol. Scalabiliby being a very important feature at that. Scott Brant Stevens wrote: > The use of IP address summarization creates FS query boundaries, and gives > you a sense of hierarchy, but, you are correct in that there is not an > area-based hierarchical system... > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > Scott Jensen > Sent: Thursday, March 15, 2001 12:58 PM > To: David Cooper > Cc: Howard C. Berkowitz; [EMAIL PROTECTED] > Subject: Re: OSPF > > also note in your reading that EIGRP is Flat where OSPF is hierarchical > similar to BGP. > > Scott > > David Cooper wrote: > > > just what I was looking for :) > > > > Thanks, > > Dave > > > > On Wednesday 14 March 2001 23:34, Howard C. Berkowitz wrote: > > > >Hey all, > > > > > > > > I've been reading into BSCN here lately with Cisco press > > > >books. In the book > > > >there is a fairly detailed discussion of OSPF. I'm not in the least > > > > opposed to learning it. One thing I would like to understand is why an > > > > organization would use it. Is this used in ISP's? What are the > advantages > > > > of it over say, EIGRP? I always see it compared to RIPv1 but I find it > > > > silly for advanced routing protocols to be compared with ripV1. > > > > > > I'll preface my remarks with the observation that all three advanced > > > IGPs: OSPF, EIGRP, and ISIS, all work well. ISIS is more a niche > > > protocol for ISPs. There are pros and cons for each one. > > > > > > OSPF and ISIS require structured network topology from the very > > > beginning, while EIGRP is much more tolerant -- up to a point. For > > > me, the definitive comment came over a few beers shared with a > > > distinguished Cisco engineer. He observed, "to build a really big > > > network, you absolutely have to have clue." He burped loudly, and > > > then went on. "EIGRP has the advantage of letting you stay clueless > > > for longer." > > > > > > The biggest argument against EIGRP is that it is Cisco proprietary. > > > Being proprietary has implications beyond the multivendor question. > > > Because some of the EIGRP mechanisms have not been published by > > > Cisco, there isn't the external knowledge base about EIGRP that there > > > is about OSPF and ISIS. Protocol and network architects have a very > > > deep understanding how OSPF and ISIS will behave and what their > > > strengths and weaknesses are, but no one who hasn't been a Cisco > > > employee can have the same sort of insight. > > > > > > For similar topologies, EIGRP generally needs less processing than > > > OSPF. On the other hand, with ever-faster processors, this may not be > > > a significant constraint. In a fair test, with equivalent timers set > > > to equivalent values, both converge very fast, and convergence time > > > should not be an issue with any protocol (assuming reasonable network > > > topology). EIGRP may be able to find an alternate path faster when > > > that path goes through a neighbor, but OSPF is faster if the > > > alternate path might be several hops away. > > > > > > If you run Appletalk or IPX routing, there is a definite advantage to > > > using EIGRP. EIGRP also can bring incremental updating to a Netware > > > 3.x environment that can't be upgraded. > > > > > > A few things to consider. > > > > > > >Please forgive me if this is shortsighted of me. > > > > > > > >Thanks in advance, > > > >Dave > > > > > > > >_________________________________ > > > >FAQ, list archives, and subscription info: > > > >http://www.groupstudy.com/list/cisco.html > > > >Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > > > > > _________________________________ > > > FAQ, list archives, and subscription info: > > > http://www.groupstudy.com/list/cisco.html Report misconduct and > > > Nondisclosure violations to [EMAIL PROTECTED] > > > > _________________________________ > > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] > > _________________________________ > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _________________________________ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
