[c-nsp] Cisco Nexus as MetroE switch?

[Nathan Ward]

> On 17/10/2015, at 17:54, Mark Tinka <mark.tinka at seacom.mu> wrote:
> 
> 
> 
> On 17/Oct/15 06:26, Nathan Ward wrote:
> 
>> I’m surprised no one has yet mentioned Juniper ACX - or at least I couldn’t see it in a quick scan of the thread.
> 
> It was mentioned…

Sorry, I should look better.

>> 
>> These look like a good metro-e/MPLS box as an alternative for ME3600X, and at a good price. The 5K variant, which is where you’d be looking, have 48/96 1G/10G interfaces, and 6x40G. The 1/10G interfaces are 1G for free, and 10G per port with a license - note that the cost per port is the same on 1/8/16/etc. port bundles so you can grow as you need. The 40G are free.
>> 
>> I believe it is the same hardware as the QFX, but different software.
>> 
>> I’m about to order a handful so can report back on how well they work.
> 
> I advised against it due to the Broadcom chipset that has limited label
> depth, and as such, won't support certain features such as NG-MVPN. As
> that mattered to us, we dropped the box immediately, since Juniper could
> not compromise despite me asking them, time and time again, to get more
> serious about Metro-E.

I’ve heard this about the label depth limitation. It’s not clear to me what this means in practice - the max depth is 3 labels, but, does that mean it can’t forward packets with more than 3 labels, or does this mean that only certain features (perhaps hashing for load balancing across multiple physicals in a bundle) can happen with 3 or less labels? The latter makes sense, the former seems kind of odd.
I know that there is a limitation where flow labels cannot be used, and where it won’t load-balance across multiple paths. We do TE, and if we need to we’ll load balance across multiple tunnels at the head end, so I can’t see that being relevant either - it’s just another TE path from the ACX point of view.

We’re also not doing more than 3 labels, so I’m not worried, but curious about what the limitation actually means.

If you have any info on that I’d love to hear it - we can move that discussion to j-nsp though perhaps :-)

> So there could be other forwarding restrictions the Broadcom may
> introduce into your network that you may not have thought about now. I'd
> suggest you think about and test anything and everything you (think you
> will) run before buying. The OS environment will feel like an M/MX, but
> I'm betting you'll only be able to do 75% of the things you can do on a
> router.

Sure. In my environment we’re doing simple ethernet pseudowires, without anything fancy so I expect it will behave just fine for that - that is the core metro-e feature, really.

--
Nathan Ward