Shhh... Cisco's latest switch supports VMware NSX

A recent switch upgrade by Cisco has added an interesting twist to the company's battle royale with VMware over next-generation virtual networking and data center operations management.

Cisco late last month announced the Nexus 3100 top-of-rack data center switch, a follow-up to the 3000 series of the Nexus switches. In doing so, Cisco boasted about the 3100's low-latency and high-frequency processing power, and also confirmed that the switch supports OpenFlow and overlay software-defined networking (SDN) models, such as VMware's NSX.

Here's why that could be a big deal: VMware's NSX network virtualization strategy is an overlay approach, meaning that it's software that runs on top of existing network hardware. Since VMware unveiled NSX at VMworld in August, some have questioned how the integration between NSX software and network hardware would actually work.

[RELATED:Will VMware's big gamble on network virtualization pay off?]

NSX makes those connections in a variety of ways, including via software gateways and a protocol named OVSDB, which provides a link between the software and hardware switches.

That's usually enough capacity for NSX deployments, especially early test cases. But for larger rollouts, NSX can benefit from having a top-of-rack switch to unite the software and hardware. From the start, VMware has had solid support for NSX from top-of-rack switch makers such as Arista, Brocade, Dell, HP and Juniper. Cisco, however, was missing from the line-up a point VMware officials dismissed as no big deal in that not all NSX deployments require top-of-rack switches anyway.

Fast forward a couple of weeks and Cisco now has the Nexus 3100, which a company official confirmed supports OpenFlow and the "full programmability" for SDN overlay models such as NSX (Cisco's marketing materials do not specifically mention the VMware technology).

This is interesting because Cisco has pointed out the limitations of a software-only approach, noting the benefits of an Application Centric Infrastructure (ACI) model, which just so happens to be what Cisco spin-in Insieme Networks is doing.

So does the 3100 represent a change in Cisco strategy? Not quite, IDC analyst Brad Casemore says. Cisco's primary motive in releasing the Nexus 3100 is likely aimed at dulling attention that competing network hardware vendor Arista has recently been receiving in high-throughput switches. "I don't think Cisco's intent is to help the folks at VMware with this switch," Casemore says.

The bigger point is that while Cisco's new switch technically works in a VMware virtual networking environment, the competition between these companies is just getting started.

"We are at a point where sides are being chosen in SDN and network virtualization," says Eric Hanselman of the 451 Research Group. Vendors like Citrix are lining up behind Cisco while HP, Dell and Brocade behind VMware and NSX in terms of supporting top of rack switches.

Cisco may be supporting some NSX use cases with the Nexus 3100, but the company is still focused on its own approach.

Meanwhile, as Cisco and VMware compete on the networking side, they're still partnering in other areas, like VCE a converged infrastructure spin-out backed by EMC, Cisco and VMware. "None of these players can afford to isolate or diminish their relationships, so we're getting into a very complicated set of integrations between these players," Hanselman says. "The question, more broadly, is how all these relationships evolve over time."

Senior Writer Brandon Butler covers cloud computing for Network World and NetworkWorld.com. He can be reached at BButler@nww.com and found on Twitter at @BButlerNWW. Read his Cloud Chronicles here.  

Read more about lan and wan in Network World's LAN & WAN section.