OSPF vs IS-IS

Doug Marschke doug at proteus.net
Tue Aug 16 22:22:55 CDT 2011


I know we are just talking about the core, but out of curiosity will you
have any MPLS/BGP VPNS that you may want to run the IGP over.  

In this case, OSPF may make a little more sense.

However if you are really just talking the core, I would agree with the rest
of the list, as the decoupling of IP has some advantages and does the TLV
structure.



Doug Marschke
Chief Operating Officer
JNCIE-ER #3, JNCIE-M #41, JNCI
(415) 704-5005 (office)
(415) 902-5702 (cell)
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www.proteus.net
-----Original Message-----
From: CJ [mailto:cjinfantino at gmail.com] 
Sent: Friday, August 12, 2011 5:24 AM
To: jim deleskie
Cc: nanog at nanog.org; Jeffrey S. Young
Subject: Re: OSPF vs IS-IS

You guys are making a lot of good points.

I will check into the Doyle book to formulate an opinion. So, I am
completely new to the SP environment and OSPF is what I have learned because
I have ever only had experience in the enterprise.

It seems that from this discussion, IS-IS is still a real, very viable
option. So, IS-IS being preferred...realistically, what is the learning
curve?


CJ

On Fri, Aug 12, 2011 at 7:57 AM, jim deleskie <deleskie at gmail.com> wrote:

> If a network is big enough big / complex enough that you really need
> to worry about performance of mesh groups or tweaking areas then its
> big enough that having a noc eng page you out at 2am when there is an
> issue doesn't really scale.  I'm all for ISIS, if I was to build a
> network from scratch I'd likely default to it.  I'm just say, new
> features or performance aside the knowledge of your team under you
> will have much more impact on how your network runs then probably any
> other factor.  I've seen this time and time again when 'new tech' has
> been introduced into networks, from vendors to protocols.  Most every
> time with engineers saying we have smart people they will learn it /
> adjust.  Almost every case of that turned into 6 mts of crap for both
> ops and eng while the ops guys became clueful in the new tech, but as
> a friend frequently says Your network, your choice.
>
> -jim
>
> On Thu, Aug 11, 2011 at 7:12 PM, Jeffrey S. Young <young at jsyoung.net>
> wrote:
> >
> >
> > On 12/08/2011, at 12:08 AM, CJ <cjinfantino at gmail.com> wrote:
> >
> >> Awesome, I was thinking the same thing. Most experience is OSPF so it
> only
> >> makes sense.
> >>
> >> That is a good tip about OSPFv3 too. I will have to look more deeply
> into
> >> OSPFv3.
> >>
> >> Thanks,
> >>
> >> -CJ
> >>
> >> On Thu, Aug 11, 2011 at 9:34 AM, jim deleskie <deleskie at gmail.com>
> wrote:
> >>
> >>> Having run both on some good sized networks, I can tell you to run
> >>> what your ops folks know best.  We can debate all day the technical
> >>> merits of one v another, but end of day, it always comes down to your
> >>> most jr ops eng having to make a change at 2 am, you need to design
> >>> for this case, if your using OSPF today and they know OSPF I'd say
> >>> stick with it to reduce the chance of things blowing up at 2am when
> >>> someone tries to 'fix' something else.
> >>>
> >>> -jim
> >>>
> >>> On Thu, Aug 11, 2011 at 10:29 AM, William Cooper <wcooper02 at gmail.com>
> >>> wrote:
> >>>> I'm totally in concurrence with Stephan's point.
> >>>>
> >>>> Couple of things to consider: a) deciding to migrate to either ISIS
or
> >>>> OSPFv3 from another protocol is still migrating to a new protocol
> >>>> and b) even in the case of migrating to OSPFv3, there are fairly
> >>>> significant changes in behavior from OSPFv2 to be aware of (most
> >>>> notably
> >>>> authentication, but that's fodder for another conversation).
> >>>>
> >>>> -Tony
> >
> > This topic is a 'once a month' on NANOG, I'm sure we could check
> > the archives for some point-in-time research but  I'm curious to learn
> > if anyone maintains statistics?
> >
> > It would be interesting to see statistics on how many service providers
> run
> > either protocol.  IS-IS has, for some years, been the de facto choice
for
> SP's
> > and as a result the vendor and standardisation community 'used to'
> develop
> > SP features more often for IS-IS.  IS-IS was, therefore, more 'mature'
> than OSPF
> > for SP's.  I wonder if this is still the case?
> >
> > For me, designing an IGP with IS-IS is much easier than it is with OSPF.
> > Mesh groups are far easier to plan (more straightforward) easier to
> change
> > than OSPF areas.  As for junior noc staff touching much of anything to
do
> > with an ISP's IGP at 2am, wake me up instead.
> >
> > jy
> >>>>
> >
>



-- 
CJ

http://convergingontheedge.com <http://www.convergingontheedge.com>





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