Discussion in 'Cisco' started by jimbo, Apr 1, 2005.

  1. jimbo

    jimbo Guest

    Thinking about switching from RIP to a contemporary protocol. OSPF
    seems to be the darling of the industry, but in many ways EIGRP seems a
    fine competitor, IF your shop is all Cisco routers. I note the
    following advantages to EIGRP.

    1 - Route summarization at bit level, and summarize at any router
    2 - True loop-free environment via DUAL (OSPF gets close, but can loop)
    3 - Quieter than OSPF on stable network. OSP must send link state
    database every 30 minutes
    4 - Although EIGRP can't be configured into areas, traffic can be
    bounded via autonomous system numbers
    5 - Unequal multi-path routing
    6 - Easier upgrade from IGRP since metrics are similar

    Do you agree / disagree? Thanx!
    jimbo, Apr 1, 2005
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  2. jimbo

    John Agosta Guest

    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.

    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
    John Agosta, Apr 2, 2005
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  3. jimbo

    thrill5 Guest

    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

    thrill5, Apr 2, 2005
  4. 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.
    Vincent C Jones, Apr 2, 2005
  5. jimbo


    Mar 24, 2009
    Likes Received:
    I just love reading posts like this.
    Missiongeek, Mar 24, 2009
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