[192619] in North American Network Operators' Group
Re: OSPF vs ISIS - Which do you prefer & why?
daemon@ATHENA.MIT.EDU (Mark Tinka)
Thu Nov 10 09:33:36 2016
X-Original-To: nanog@nanog.org
To: James Bensley <jwbensley@gmail.com>, "nanog@nanog.org" <nanog@nanog.org>
From: Mark Tinka <mark.tinka@seacom.mu>
Date: Thu, 10 Nov 2016 16:33:27 +0200
In-Reply-To: <CAAWx_pU4L09za-Wc34UcSaZkOy9bLTAk54WLo6zZ7cTGtaxLkA@mail.gmail.com>
Errors-To: nanog-bounces@nanog.org
On 10/Nov/16 12:17, James Bensley wrote:
>
> I don't think there is much of a debate to be had any more, the gap
> between them is so small now (OSPFv3 and ISIS that is, no one would
> deploy OSPFv2 now in greenfield right?):
Most networks that I know are greenfielding an IGP will deploy both
OSPFv2 and OSPFv3. Worst case, just OSPFv2.
>
> This is in OSPv3.
Right, but if a network does not yet want to run IPv6 (2016, anyone),
then this becomes an issue as IPv6 NLRI is carried over the IPv6 transpor=
t.
This could also come down to implementation. I looked at this for the
first time back in Junos 9.0 (when it was still an IETF draft), and no
other vendor had it yet. It has since matured and I know both Juniper
and Cisco have decent code.
I can't speak for other vendors, particularly if you multi-vendor.
> Single area 0 deployment at scale? Bit of a moot point unless you
> compare a specific device model and specific code version in two
> identical deployments, its not much to do with the protocol but the
> vendor implementation and the brute force.
Like I said to Randy, if I did deploy OSPF ever (quite unlikely), there
is enough CPU in today's router to, I think, run a single Area 0 for the
whole thing.
> OSPv3 has this.
Yep, as I did mention.
> OSPF has these too.
More of them in OSPFv3 than OSPFv2. But then again, vendor-specific
knobs can be had here for cheap.
> Yeah this ^ I don't think there is a stronge case for either protocol.
>
> Somenoe mentioned the AOL NANOG talk about migrating from OSPF to
> ISIS. There was a NANOG talk recently-ish about someone migrating from
> OSPF to BGP. There wasn't even a need for an IGP, BGP scalled better
> for them (in the DC).
>
> BGP these days supports PIC and BFD etc, how much longer to IGPs have? =
:)
Sounds like you're talking about BGP-LS.
If you are, then BGP-LS still requires an IGP. It's just that the IGP
has a much more micro view of the network, while BGP-LS is tasked with
the macro side of things.
Mark.
