Cisco Systems was a notable exception from the NSX partner hoopla. Asked about VMware's relationship with the networking giant during a press Q&A Tuesday, VMware CEO Pat Gelsinger said, "We'll do everything in our power to build the partnership we have with Cisco."
"NSX will be a great platform for Cisco infrastructure," he added.
Gelsinger emphasized that NSX is in its early days, comparing it to VMware's server virtualization software. "This is like ESX in 2004. We're just beginning to mine a rich vein of innovation that we think has a decade ahead of us."
During a session on network virtualization and NSX Wednesday at VMworld, an attendee asked Allwyn Sequeira, VP and CTO of networking and security at VMware, about integration with Cisco.
"Obviously, you have to work with Cisco. Our customers demand that," Sequeira said, but added that he would leave any official statements to Cisco.
Cisco declined to comment directly to Network Computing, but on Thursday CTO Padmasree Warrior posted a blog. Cisco's stance on NSX was made clear in the blog's headline: "Limitations of a Software-Only Approach to Data Center Networking."
Warrior emphasized Cisco's ongoing relationship with VMware, writing "VMware is an important partner to Cisco, and we expect to continue our close collaboration around private cloud and desktop virtualization."
However, she also declared that a software-only approach puts a restriction on customers. "It doesn't scale, and it fails to provide full real-time visibility of both physical and virtual infrastructure," she wrote. "In addition this approach does not provide key capabilities such as multi-hypervisor support, integrated security, systems point-of-view or end-to-end telemetry for application placement and troubleshooting."
[Martin Casado, VMware's chief architect for networking, addresses critiques of NSX and discusses other issues in a Network Computing interview. Check out "VMware's Martin Casado: Energy and Chaos."]
She also wrote that customers would be forced to tie together components from other vendors, which would add "...cost and complexity in both day-to-day operations as well as throughout the network lifecycle."
Cisco wasn't without a presence at VMworld. It has a prominent booth on the show floor, showing off its Nexus switches, integration between Unified Communication System (UCS) and VMware, and cloud management tools.
"As is said on Facebook, it's complicated," said Eric Hanselman, chief analyst at 451 Research, in regard to the Cisco/VMware relationship.
"There is certainly a long-term impact that network virtualization could have on making it easier for customers to bring other networking vendors into their worlds," said Hanselman. "At over 80% market share, though, VMware and any other players will be working with Cisco for a long time to come. Much of Cisco's UCS business is driven by VMware sales, so the dependencies are not one-sided."
Joshua McKenty, co-founder and CTO of startup Piston Cloud Computing--which makes a public cloud operating system based on OpenStack--said Cisco will go its own route on software-defined networking. "They don't need NSX," he said in an interview on the show floor. Piston partners with both Cisco and VMware.
"With its massive installed base, they can be more strategic," McKenty said. "They can take a wait-and-see approach. They know when they need to throw money in, they can."
"Clearly, VMware and Cisco are going head to head," Michael Bushong, VP of marketing at Plexxi, which makes an SDN controller, said in an interview on the show floor. "They have philosophically different points of view."
At Cisco Live earlier this summer, Cisco provided more details about its SDN plans by unveiling Dynamic Fabric Automation. Cisco calls its SDN strategy "Application-Centric Infrastructure."
Many in the industry assume Insieme, a Cisco-backed venture, is doing something related to SDN, but Cisco has yet to provide significant details about it.
For its part, HP is working with VMware to federate its Virtual Application Networks SDN Controller with NSX, Bethany Mayer, senior VP and general manager of HP Networking, said in an interview at VMworld.
As an overlay technology, NSX doesn't provide visibility to the network beneath it, she said. The federated HP-VMware technology, slated for the second half of 2014, will provide a centralized view of the network and facilitate automation, she added.
Worried about how SDN might affect your career in networking? Want insights on how to stay relevant as virtualization upends the data center network? Don't miss the panel discussion and Q&A session "Will SDN Make Me Homeless?" at Interop New York this October.