vSphere 5.1 Load Balancing with UCS

[David Rodriguez]

Hi,

We are running Cisco UCS 2.1(2a), B200 M3 blades, Nexus 5k switching and vSphere 5.1 Update 1

If we are not running Cisco 1000v virtual switching and just using VMware vDS, what should the port-channel load balancing method be set to on the Nexus 5k and what should it be set to in vSphere 5.1 - networking - load balancing ?       

[Mastin Bailey]

Hi David,

Since you're not using the N1KV and are instead using the VMware vDS, VMware recommends using LBT, which requires no special upstream switch configuration.  You can see this recommendation via their White Paper.

vSphere Distributed Switch Best Practices:

http://www.vmware.com/files/pdf/techpaper/vsphere-distributed-switch-best-practices.pdf

Here are a couple of good blog posts comparing the different options, and they outline LBT as well.

http://longwhiteclouds.com/2012/04/10/etherchannel-and-ip-hash-or-load-based-teaming/

http://frankdenneman.nl/2011/02/24/ip-hash-versus-lbt/

VMware KB and Performance Blog:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1022590

http://blogs.vmware.com/performance/2010/12/vmware-load-based-teaming-lbt-performance.html

I hope this helps.

-MB

[David Rodriguez]

Thanks for your replay masbaile and the links. LBT makes sense after reading through your documents.

In regards to the uplinks from the interconnects to the Nexus5k's these are port-channel but according to the document the port-channel load-balance method on the 5k's isn't used from VMware vds point of view if LBT is selected. What about from the interconnects point of few, is there a preferred method ?

[Mastin Bailey]

Hi David,

Sorry for the late response.  I was on PTO, and then I was at VMworld.  From the FI's to the 5K's upstream, PO's / vPC would be recommended if you have that option.  LBT won't care how you're configured upstream, as it requires no special upstream configuration.