Protocols: EIGRP vs OSPF

  • EIGRP and OSPF are both IGP protocols, the former is a mostly Cisco protocol and the latter is a well established open standard. What are the benefits of one over the other?

    Put another way, when deploying a network, why choose one over the other? If you have mixed devices the choice would obviously be OSPF, but what if you are running a Cisco only shop? Are there any features where EIGRP excels compared to OSPF that would make it feasible to only deploy EIGRP?

    Most of the routing books deal with comparision of the link-state and "hybrid" or in this particular situation - EIGRP. Why don't you take a time to read them first?

    While the question is valid and the answering information valuable. I feel that this question as written today is too broad for the Stack Exchange Q/A format. Specifically, asking "What protocol should one choose when deploying a network?" is a question that has many variables and many answers, all depending on the specific situation at hand.

    It's more about the choice between EIGRP and OSPF, the title of the question doesn't ask for what protocol to use but asks for a comparison of OSPF vs EIGRP and the benefits of each protocols. So I must disagree.

    I would agree that the question is not useful. The nerd knob stuff does not matter in 95% of networks, its either I need to run OSPF to talk to non cisco gear or matter of religion where you have all cisco gear.

    If you can set aside your personal religion, on purely technical merit, they're more-or-less even. However, people are rarely so objective on this particular subject.

  • Daniel Dib

    Daniel Dib Correct answer

    9 years ago

    EIGRP is now an IETF draft so it's no longer proprietary. See http://tools.ietf.org/html/draft-savage-eigrp-01

    If we look at EIGRP with default settings and OSPF with default settings and there are multiple loop free paths to a destination then EIGRP will converge much faster because it keeps what are called feasible successors in it's topology database. These are basically loop free alternatives to the best path. EIGRP also has summarization at any point in the network. It also has stub feature which is useful when you don't want to use a router for transit. Commonly deployed in DMVPNS. EIGRP is also less confusing than OSPF because it does not have different network types and EIGRP is easier to deploy in hub and spoke scenarios.

    EIGRP uses a flat network without areas, this can both be an advantage and disadvantage.

    OSPF is obviously an open standard so it's the logical choice if you have multiple vendors. It can perform well but it requires that you tweak SPF timers because by default in IOS there is a 5 second wait before running the SPF algorithm. OSPF uses areas which means you can segment the network more logically. OSPF can only summarize between areas. OSPF is link state so it has a better view of the entire network than EIGRP before it runs the SPF algorithm. Network administrators will usually be more comfortable with OSPF because it's more commonly deployed.

    Both protocols have advantages and disadvantages. But the common answer that EIGRP should be discarded because being proprietary is not entirely true any longer.

    No longer proprietary but also not implemented by any other companies outside of cisco. So the end result is the same.

    It's coming. Not sure which ones but Donnie Savage mentioned that 5 companies or so are releasing products with it. That said I expect it to be companies like Huawei or other asian based companies. Because EIGRP has been proprietary people have been lazy when comparing the two. I compare them technically and for an enterprise EIGRP is not a bad choice. for an ISP I would go with ISIS.

    Just a quick FYI, this was also discussed on Whirlpool recently - http://forums.whirlpool.net.au/forum-replies.cfm?t=2091564#r10

    @DanielDib, speaking of IS-IS, why do ISPs favor that over OSPF? In 90 words or less. ;-)

    Ease of adding new features due to TLVs. One protocol for both v4 and v6 although OSPFv3 can now run v4 as well.

    > EIGRP is now an IETF draft so it's no longer proprietary. See http://www.ietf.org/id/draft-savage-eigrp-00.txt Yep, but: > 1. Advanced features of EIGRP (namely stub areas) will not be released to the IETF. 2. Informational RFC allows Cisco to retain control of the EIGRP protocol. 3. EIGRP is still technically proprietary.
    > So, the advanced features of EIGRP are not being released – no stub areas, no way to control propagation or logically define areas. No DMVPN topologies that will scale. This is one of the primary reasons you would use EIGRP.
    More: [Why Is Cisco Bothering With “Op

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Content dated before 7/24/2021 11:53 AM