OSPF vs. EIGRP

EIGRP does have an advantage over OSPF in it's ability to sumarize routes.

I wouldn't put this into an 'advantage' category. Personally, I've never seen an OSPF "loop." EIGRP can get "sia."

Really not an issue, IMHO.

And manually redistributing between AS boundaries leaves a crack in the door for administrative snafu.

A valuable feature within the 'core,' or where there are multiple 'high speed' facilities in use. Can be bad when low speed facilities are installed in a route table.

Non-issue.

Eigrp requires a well thought out address scheme, with contiguous subnet space and route summarizatuion to avoid SIA. OSPF is a little more forgiving in this respect.

Also, OSPF is a standard.

For all the neat things EIGRP does, I'll stick with open standards, thank you.

The other advantage of EIGRP is that is scales very well in large networks, with the caveat that you have a well thought out IP addressing scheme. With this in mind it is not necessary to create "routing areas" with EIGRP. My network consists of over 900 locations with approximately 1400 routers in a single EIGRP AS. Our network is extremely stable, but this is with a well thought out addressing scheme to optimize the use of summary routes and distribute lists to minimize the routing tables on low-end platforms. Our network has been on many occasions (due to mergers/acquisitions) both an OSPF and EIGRP network, and prefer EIGRP because IMHO it is easier to manage.

Scott

EIGRP versus OSPF has been hashed out in this newsgroup every couple of years for the past ten years... A quick search of Google News (try, for example, EIGRP versus OSPF) will turn up several well thought out threads which discuss the advantages and disadvantages of each.

The bottom line is that for most networks there is no significant advantage to either, but there are a few pathological topologies where one or the other stumbles badly. For example, OSPF can have problems with large hub and spoke networks with high density hub routers and multiple links to each spoke. Similarly, EIGRP can be problematic if there are large numbers of alternate paths which can not be configured to be feasible successors.

There is also the "obvious" limitation that whichever protocol is selected must be available on all routers you plan to use. Perhaps most important, neither protocol is "scaleable" if you don't understand each protocol's specific limitations and architect your network to avoid them.