Cisco has bought start-up vCider for its expertise in developing virtual network overlay technology for secure data center infrastructure. The price wasn't disclosed.

GigaOm rates it as a counter to VMware buying Nicira, which, it says, "has strained the once close partnership between Cisco and VMware." It figures it'll be used "to build a unified yet distributed Cisco-based cloud."

The new prize will be integrated into Cisco's Cloud Computing organization, reporting to cloud CTO Lew Tucker, the vice-chairman of the new OpenStack Foundation.

In a blog posting Cisco said it expects vCider to play an important part in its Open Network Environment (ONE) strategy, particularly in support of OpenStack, a key pillar of Cisco's open, multi-hypervisor, multi-stack cloud computing strategy.

Cisco joined OpenStack 18 months ago and has contributed to the OpenStack Quantum API track.

Cisco figures Quantum is becoming a core OpenStack service and says "it's clear that programmable networking is quickly becoming an important component in large scale, multi-tenant, cloud computing environments."

Its Quantum plug-in is designed to give application developers increased programmability of both virtual and physical networks linking the cloud to ONE.

It says vCider has created a multi-tenant distributed virtual network controller. Its code and technology will be integrated into Cisco's Quantum development efforts.

Pre-Cisco vCider widgetry helped companies bridge different cloud providers with more security and less latency than you'd get from a virtual router.