The next wave of software-defined networking (SDN) startups continues to emerge, as AllThingsD reports this morning that Alan Cohen, formerly of Nicira, has become chief commercial officer for a startup called Illumio.

It's the second stealth-mode company to emerge in recent weeks, after Canadian firm Corsa Technology announced itself with a round of funding. AllThingsD noticed Illumio after Cohen changed his LinkedIn profile. Cohen had been vice president of marketing at Nicira and left shortly after its acquisition by VMware.

Illumio is a typical stealth-mode case, working on some vague idea of cloud security. So, it's not an "SDN" startup for certain -- although that would seem a decent guess, considering pretty much everybody now claims to be doing SDN.

The Santa Clara, Calif.-based startup raised $8 million from investors including Andreessen Horowitz and Juniper Networks' Junos Innovation Fund.

Assuming Illumio is working on security for virtualized environments, it's going to have plenty of company. Many vendors say security -- of the controller and of virtual machines -- is a major concern to potential SDN customers. That's led to startups like vArmour targeting security specifically. Layer 4-7 players such as Embrane will necessarily have a security story, too, though not necessarily overlapping with Illumio's.

The security angle hasn't escaped the eyes of established players, either. Security vendors such as Radware have felt compelled to build SDN strategies. Cisco is seriously boosting its security holdings with the acquisition of Sourcefire, announced last week -- a move that might target services but is likely to have some impact on Cisco's SDN plans. And Juniper itself is likely to get active in SDN and security, given its obsession with both types of technologies.