The State of Illinois converted to ISIS in 2002 from EIGRP and it has definitely been a good thing for us. It's been operationally bullet proof, and simple to maintain. We typically get features faster than we would if we ran OSPF. For example, we have a desire in the future to use IPFRR. Every indication from the vendor is that this feature will be available to ISIS first, most likely because of either the extensibility of ISIS or more likely because ISIS is in so many larger providers. Mike Bernico -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of vijay gill Sent: Tuesday, June 21, 2005 9:20 AM To: Dan Evans Cc: nanog@merit.edu Subject: Re: OSPF -vs- ISIS Dan Evans wrote:
All,
Can anyone point me to information on what the top N service providers are using for their IGP? I'm trying to build a case for switching from OSPF to IS-IS. Those on this list who are currently running IS-IS, do you find better scalability and stability running IS-IS than OSPF? I understand that this question is a lot more complex than a simple yes or no since factors like design and routing policy will certainly affect the protocols behavior.
Any insights or experiences that you can share would be most helpful.
Thanks,
Daniel Evans Alltel Communications
Daniel, in short, we've found ISIS to be slightly easier to maintain and run, with slightly more peace of mind in terms of securitiy than OSPF. Performance and stability wise, no major difference that was noticable. For more information, see the talk by Dave Katz at http://www.nanog.org/mtg-0006/katz.html Also, AOL's experience in switching from OSPF to ISIS is covered at http://www.nanog.org/mtg-0310/gill.html the PDF on that page is actually an older version. The full version I used at NANOG is available at http://www.vijaygill.com/oi.pdf /vijay