4500-X vs 6880-X for Core/Distribution

[MURRAY CHAPMAN]

Hi,

    We are in the process of looking at upgrading our eight year old Cisco network to something newer.

    Currently we have a 6500 for core/distribution with about 40+ 1 gig fibre links running out to access layer switches. (3560 and 3560X)

    The whole design is routed with the links from core/distribtion to access all being layer 3.  The intent was to dual attach access layer switches to 6500s in two buildings but this was never actually implemented.

     The new design uses 3650 switches at the access layer, and a recommendation to use the 6880-X for core/distribution.  This time around key buildings will be dual attached and I expect we will keep the routed design.  9396PX will be introduced at the datacenter layer.

     It looks to be like the 6880-X is a pretty limited unit.  No real path to 40 or 100 gig, no redundant supervisors, just a big box of 10 Gig ports.

     I am assuming the cost on a 6807 chassis is just going to be too high, although 40 G and 100G are either available today or on the roadmap.

     I am trying to figure out why two 4500-X with Enterprise software in VSS mode isn't a better fit.  The port count is good at 80 (between the two), it has more bandwidth, features like MACSEC and SGT are on the develpment radar (if not already implemented), and two of these in VSS means I can perform a firmware update with minimal down time.

     I plan to implement ISE in 2015 so having a platform that is going to work with ISE is really important to me.

Thanks

Murray

[mateja.jovanovic]

Wow, amazing that noone answered such a real world question. I had like 2 similar cases within the last 2 months!!!

I normaly really like 4500X, it´s a powefull 1U 10G unit, and I myself am a fan of VSS, so - I agree with you, that should be a first choice! (btw - 6880 also supports VSS)

When to use 6880X? Well, I had a case recently with 45 3750X stacks in the core, so 80 ports in total wouldnt even cover a port-channel per stack, so - I used 6880X. How do I see this switch? As a moderatly priced almost-Nexus alternative for Campus with 10G with a VSS support. 

To sum it up - yeah, I´d use 4500X if I were you...

Cheers!

[leighsanders]

Hi Murray

Just saw this thread and wondered how this went? Reading through it seemed odd to me that no-one had raised the subjects of Instant Access, modularity, scalability, Dual vs Quad Sup VSS, feature breadth etc. In other words, the many reasons why the 6880 would be a great option in lots of scenarios. Be intereste in what choices you made, or whether youre still undecided?

All the best

[MURRAY CHAPMAN]

Hi everyone,

      Using the 68XX series was Cisco's textbook recommendation for implementing our new design. But when we looked at what we actually we trying to do, we needed a minimum of 4 of the 6880-X (dual network cores in each data centre) and we wanted 40G to be future ready so that put us into the chassis based 6807 and we just didn't have that much cash.

     So what we ultimately did was buy a total of 6 x 9396PX Nexus switches. 4 of them have the Enterprise routing option and act as cores in VSS pairs.  Two of them are basically used as top of rack switches to get lots of 10G ports.  All the 9396PX are connected with 2 x 40G links.  Cisco had a really good deal on the 9396PX bundles because they were new.

     Looking back with 20/20 hindsight I am not sure we would have gone this way again.  The config on these is different from other nexus models, and there was no local talent who understood the subtleties so we had some stupid problems that it took a while to sort out.

    We also had the "primary" core spontaneously reboot on at least one occasion a second unit has gone back with a bad memory module.

     But, its now six months later, the problems seem ironed out, and for very low cost we got boxes with 48 x 10G and 12 x 40G ports and for a fraction of what we would have paid for 6880-X units (without even the 40G) we have fully redundant cores in both data centres. (In Canadian dollars at the time the 6880-X with 80 x 10G ports were about $80K each but the bundle pricing on 2 x 9396PX with a handful of multimode 40G optics was about $30K)  Before someone challenges me on my math, yes we would have got the 6880s with less ports than 80, probably 64  because we're using a bunch of the 40G ports on the 9396PX. Also we have no 10G copper at all so one of the other 9300 series wouldn't have been a good fit)

     I know we lost some features by not having the full software set a 6800 does and that may come back to burn us.  Confidence in the new solution is growing but it was shaky at first.  We had a few other things that showed up at the same time and it was hard to isolate what was Cisco and what was "other". 

     I copied this approach in general from a fellow named Nathan Cowger who used Nexus 7700s where I used 9396PX. Ironically his comment to me later was if the 6800 chassis was available when he did his network he would have used that. :)

Murray

[kurtnolfses]

I would go for 2 x 6880 in the core without VSS. No VSS in the core if you can avoid it. VSS = single control plane = single point of failure. Also, one  day you will come across a non ISSU / VSS compatible upgrade. The only solution is to perform a non ISSU upgrade on the VSS and lose your core for a couple of minutes until everything is up and running again. Or a nice VSS bug that hits the control plane. One a L3 core, you can upgrade one core and check the stabilty of the new IOS for a couple of weeks. On a VSS, it is all or nothing.

In the core,I stay away from L2 as much as possible, L3 only. 4500 does not have routed sub-interfaces which I found to be a big disadvantage if you want to use them as core devices. Yes, PtP VLANs do the job but it is still a hassle ( BPDU filter, ... ) . From the L3 distribution / L2 aggregation ( stacks, 4500-X VSS, ...), run L3 PtP uplinks to both core devices and use ECMP if needed.

[Robert Rowland III]

Can you tell us the direction you chose ?

  Not sure how a 4500X was going to be involved with ISE in a end user facing role .. it seems not to be an appropriate desktop switch.