OSPF -vs- ISIS

Tue Jun 21 14:19:54 UTC 2005

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