OSPF vs IS-IS

Jeffrey S. Young young at jsyoung.net
Sat Aug 13 12:44:06 UTC 2011


That's interesting and if true would represent a real change.  Can you list
the larger SPs in the US that use OSPF?

jy

On 12/08/2011, at 10:40 PM, James Jones <james at freedomnet.co.nz> wrote:

> I would not say ISIS is the prefered protocol. Most service providers I have worked with use OSPF. Most networks outside of the US use it from what I have seen and the larger SPs in the US do too. There must be a reason for that.
> 
> 
> Sent from my iPhone
> 
> On Aug 12, 2011, at 8:23 AM, CJ <cjinfantino at gmail.com> wrote:
> 
>> 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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