EIGRP or OSPF

[Nutz]

What do you folks prefer to use as your routing protocol?

EIGRP or OSPF

Why would you choose one over the other?


Allow me to get this started:
If I have an all Cisco network, that is not extremely huge, I'd use EIGRP. Faster convergence for most networks, does not need as much memory since it does not know every route to every network, and you can summarize on a per interface basis, on each router.

OSPF if its not a homogenous Cisco network or if the network is huge. EIGRP drops all routes learned from a neighbor if that neighbor does not answer a query fast enough. It could be waiting for a neighbor to answer it, and so and so forth. EIGRP get mad and says, since you did not answer me, I am going to declare everything I learned from you as bad information. Then it has to start all over, do you want to be neighbors?

 

[spidey07]

OSPF - simply because of its scalibility and control. That and its not proprietary.

EIGRP is a great routing protocol, but I still prefer OSPF.

 

[Nutz]

Care to give some examples of why one may be appropriate and another not? (besides when you have a mix of different vendor's routers)

 

[cmetz]

EIGRP is always inappropriate, IMO.

EIGRP is proprietary, which you should just say no to if there's a reasonable alternative (Cisco didn't invent it, it's based on an old academic paper, someone's thesis or something, but Cisco ran with it and made many enhancements that they claim IP rights over). Rather than compete on technology, for many years Cisco deliberately "forgot" to fix serious bugs in their OSPF implementation, but their EIGRP was kept up to date. So if you were in the know, you ran EIGRP or IS-IS just because they were debugged, and not OSPF which was buggy enough to bite you. Cisco has changed their tune on this, and now that you're dealing more with apples to apples, that motivation for EIGRP has gone away. (IS-IS meanwhile evolved many useful service provider features that aren't available in OSPF yet)

Cisco used EIGRP as a marketing lock-in tool for many years; once you've got EIGRP running on your network, they own you. For this reason alone, I urge you to present your middle finger to the Cisco sales people on the subject of EIGRP. I do not appreciate vendors playing lock-in games with me, and I interpret vendors who think they have to play those games as vendors who know their products can't compete on their own merits. (which is quite true of a lot of Cisco's product line - it's just too bad that the 2600 and 3600 series really have no credible competition and are the best-merit solution)

I am NOT convinced that EIGRP is a fully stable protocol. Many of OSPF's properties that increase convergence time are done for good particular reasons, and folks come along from time to time thinking they can do better. And you can, so long as you don't handle all the corner cases properly. OSPF also has a lot of tunable variables and with thoughtful configuration you can improve its convergence time by trading off other properties; this may be appropriate for your situation. You also should double-check the OSPF feature set; these days I don't think there's anything you can't do that you'd really need to. For example, I think summarization is really rich as long as you use multiple areas (a bit of a mess itself, unfortunately).

 

[Nutz]

Thats an intersting take on it.

 

[Nutz]

^bump^

 

[Nutz]

Bump #2