Nexus, Stackable or Modular Switching for Small DC/Server Room

[Revenue_admin]

Hi Everyone,

I'm new to this so... But been tasked with designing the networking architecture for a small DC/server room. Typically 6 to 10 servers, 10G Uplink Access to Distribution, 50TB of SAN storage... that scale. This is the first time I'll be handling something like this though I have a bit of experience managing campus and branch office networks. So my confusion is this: What type of switching infrastructure would be most suitable?

1. Nexus Aggregation/Fabric Extension (feels like an overkill, but then ease of deployment and scalability?)

2. Catalyst Switches (with VSS on the agg, stacking on access layer, LACP from server to TOR and switch to Agg)?

3. Regular modular switching, with Cat 6800 for distribution and 3650 for access and any redundancy that can work asides STP?

As a newbie to DC networking, I'm really confused so any experienced advise would help. Cost is not a major concern but its always good to keep it down. Also minimum downtime is expected. In addition, I don't want to deploy STP (to avoid blocking ports and maximise port usage).

Thanks!

[Leo Laohoo]

If cost is not a problem then go with Nexus.
Start with a single 5K/6K in the core and use 2K as top-of-rack.

[Revenue_admin]

Hello Leo Laohoo, Thanks a lot for the recommendation we decided to go with regular catalyst switches since the scale of the server room in question is really small and considerable expansion is not likely in the foreseeable future.



Regards

[Leo Laohoo]

Go with Catalyst 9300/9400/9500 and then enable QoS.

[Revenue_admin]

Exactly. Though I used 3650/3850 in my design. I'm not sure if there's a major advantage of the 9000 series over them considering my use case. But if I may ask, why did you specifically say enable QoS? Wouldn't that come normally or is there a reason attached to the use of non-nexus switches?


Then another little question if you'd be so kind to help out, what's your take on having a separate server room firewall (with IPS, between the internal LAN and different VLANs in the server room) ? Is that common/good practice? That's as against using the same firewall device for both edge and this purpose - if at all? security is a major concern in this deployment scenario.


Hope my questions are not too many. Thanks

[Leo Laohoo]

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@Revenue_admin wrote:
why did you specifically say enable QoS

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Because Catalyst switches have shallow port buffers.  When (not "IF") the servers start hammering the ports with high-speed data the ports buffer will fill up very, very quickly and you'll start dropping packets by the truck load. 

QoS is the only way to control the buffers from overflowing.

[Revenue_admin]

?Thank you very much. I'll read up on that then.


Regards