UCS uplink to Nexus 2K

[leeroi1526]

Hi to All,

We are on the process of deploying 2 Nexus 7k, 2 nexus 5K and a bunch of nexus 2k in our data center, we use vPC inside our data center, we do have UCS is our DC which is currently connected to our 6509E core switch via port channel with 1GB link speed each physical link having a bundle of 4GB aggregated bandwidth. Since we will replace the 6509E with the Nexus platform, our 5K will be the aggregation and is having vPC to the 7K, while the 2k is also having vPC to 5K. My plan is to connect the the fabric of my UCS (total of 4 links in each fabric) via layer 2 port-channel via trunk mode on my nexus 2k, allowing specific VLAN on the trunk ports, this is the same set uo with my 6509E switch. My concern is does the N2K support this type of deployment? I am aware that I can connect the UCS either on my 5K's or 7K's I just want to know if there are any caveats if I use the 2K and atthe same time I don't have to procure addition SPF's if I connect it to my 2K. Please advise...

Best Regards,

[leeroi1526]

Hi,

I checked this scenario but each of the FI are having 2 uplinks within the 2 N7K's thus, it is understandable. What is on my mind is only 1 uplink in each FI, for example 6100 A uplink is connected to N7K1 while 6100 B uplink is connected to N7K2, then vPC on N7K's normal port channel on on the UCS. Please see the attached diagram.

[Walter Dey]

Sorry, this design is not possible. Consider the 2 UCS FI as separate entities (I assume ethernet end host mode), the 2 heartbeat links between the FI do not carry any user traffic; therefore UCS only supports port-channel (not vPC) per fabric interconnect, not between the 2 FI's.

[Robert Rowland III]

you could run the links from your 7Ks as just L2 trunks and let spanning tree do the work if one FI failed.

Or ... if you only have one fiber pair available each direction use 10G Bidi optics.

For instance - http://www.solid-optics.com/ftth-bidi-13#/type-bidi/speed-10g 

[Walter Dey]

you could run the links from your 7Ks as just L2 trunks and let spanning tree do the work if one FI failed.

UCS fabric interconnect in EHM don't run spanning tree !!!! all uplinks North bound from FI are forwarding.

The advantage of vPC is, that one N7k could fail, and both UCS fabrics are up

With PC or single link between FI connecting to only one N7k, you loose one UCS fabric.

Or ... if you only have one fiber pair available each direction use 10G Bidi optics.

where can I find 10G bidi Cisco certified transceivers on the support matrix ?

http://www.cisco.com/c/en/us/td/docs/interfaces_modules/transceiver_modules/compatibility/matrix/10GE_Tx_Matrix.html

[lindenk]

What was your outcome with this?

We are looking at deploying 9Ks and will be using UCS servers. Can you hookup fabric interconnects to 2Ks that are south of 9Ks or do they need to connect directly to the 9K?

[jkilleda]

Hello Jerone,

UCS uplink to Nexus 2K
Just to add up you can refer the guide below.

https://clnv.s3.amazonaws.com/2015/usa/pdf/BRKCOM-2020.pdf