[j-nsp] EX4600 or QFX5110

Graham Brown juniper-nsp at grahambrown.info
Tue Mar 12 15:40:52 EDT 2019

Hi Alex,

Just to add a little extra to what Charles has already said; The EX4600 has
been around for quite some time, whereas the QFX5110 is a much newer
product, so the suggestion for the QFX over EX could have been down to

Have a look at the datasheets for any additional benefits that may suit one
over the over, table sizes / port counts / protocol support etc etc. If in
doubt between the two, quote out the solution for each variant and see how
they best fit in terms of features and CAPEX/OPEX for your needs.

Just to echo Charles, remember that a VC / VCF is one logical switch from a
control plane perspective, so if you have two ToR per-rack, ensure that the
two are not part of the same VC or VCF. Then you can afford to lose a ToR /
series of ToRs for maintenance without breaking a sweat.


Graham Brown
Twitter - @mountainrescuer <https://twitter.com/#!/mountainrescuer>
LinkedIn <http://www.linkedin.com/in/grahamcbrown>

On Wed, 13 Mar 2019 at 08:00, Anderson, Charles R <cra at wpi.edu> wrote:

> Spanning Tree is rather frowned upon for new designs (for good reasons).
> Usually, if you have the ability to do stright L2 bridging, you can always
> do L3 on top of that.  A routed Spine/Leaf design with EVPN-VXLAN overly
> for L2 extension might be a good candidate and is typically the answer
> given these days.
> I'm not a fan of proprietary fabric designs like VCF or MC-LAG.  VC is
> okay, but I wouldn't use it across your entire set of racks because you are
> creating a single management/control plane as a single point of failure
> with shared fate for the entire 6 racks.  If you must avoid L3 for some
> reason, I would create a L2 distribution layer VC out of a couple QFX5110s
> and dual-home independent Top Of Rack switches to that VC so each rack
> switch is separate.  I've used 2-member VCs with QFX5100 without issue.
> Just be sure to enable "no-split-detection" if and only if you have exactly
> 2 members.  Then interconnect the distribution VCs at each site with
> regular LAGs.
> On Tue, Mar 12, 2019 at 06:36:49PM +0000, Alex Martino via juniper-nsp
> wrote:
> > Hi,
> >
> > I am seeking advices.
> >
> > I am working on a L2/L3 DC setup. I have six racks spread across two
> locations. I need about 20 ports of 10 Gbps (*2 for redundancy) ports per
> rack and a low bandwidth between the two locations c.a. 1 Gbps. Nothing
> special here.
> >
> > At first sight, the EX4600 seems like a perfect fit with Virtual Chassis
> feature in each rack to avoid spanning tree across all racks. Essentially,
> I would imagine one VC cluster of 6 switches per location and running
> spanning-tree for the two remote locations, where L3 is not possible.
> >
> > I have been told to check the QFX5110 without much context, other than
> not do VC but only VCF with QFXs. As such and after doing my searches, my
> findings would suggest that the EX4600 is a good candidate for VC but does
> not support VCF, where the QFX5110 would be a good candidate for VCF but
> not for VC (although the feature seems to be supported). And I have been
> told to either use VC or VCF rather than MC-LAG.
> >
> > Any suggestions?
> >
> > Thanks,
> > Alex
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp

More information about the juniper-nsp mailing list