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Network overlay vendor Midokura has partnered with Cumulus Networks to use bare-metal switches as VXLAN gateways that can bridge physical server workloads to an overlay.
Midokura creates an overlay network by distributing its MidoNet software on hypervisor hosts in a virtualized data center and tunneling traffic over the physical network using virtual extensible LAN (VXLAN). Unlike other leading overlay vendors, Midokura uses a distributed control model coordinated across every instance of MidoNet software. Connecting servers that are not virtualized to a Midokura overlay requires a gateway that can encapsulate and de-encapsulate VXLAN packets.
Few enterprises are able to run all their workloads on virtual severs, said Bob Laliberte, senior analyst at Milford, Mass.-based Enterprise Strategy Group.
"They're looking at Cumulus Linux as a way to do a gateway [between the two]," he said. "That was the overwhelming majority of solutions announced at VMworld; [switch vendors] were all announcing that they were doing gateways to [VMware's] NSX [overlay]."
Until now, Midokura has been able to write a Layer 2 gateway in software that bridges hardware server loads to virtual gateways. New merchant silicon -- specifically the Broadcom Trident II chip -- enables vendors to build switches that can do VXLAN encapsulation and de-encapsulation in hardware switch with improved performance. Cumulus' Linux-based network software runs on bare-metal switches with Trident II chips.
Cumulus' network operating system, Cumulus Linux, is designed to run on bare-metal switches built with Trident II. MidoNet integrates with Cumulus Linux via OVSDB, the management protocol for Open vSwitch (OVS). That integration allows MidoNet to use a Cumulus switch as a VXLAN gateway.
"This enables us to take a switch with that chipset, running Cumulus Linux, and take the traffic running between the physical and virtual worlds and run it at line rate, which is really useful for production workloads," said Dan Conde, director of products at Midokura. "Now, instead of having to scale out our technology using [VXLAN gateway software on] more and more on x86 servers, we can have very fast switching."
The Cumulus partnership indicates that some Midokura customers are building networks with bare-metal switches, said Lee Doyle, principal analyst at Wellesley, Mass.-based Doyle Research. "Clearly, some customers want to connect their overlays to bare-metal switches to create a hybrid environment," he said.
Midokura is also exploring the idea of running MidoNet software directly on top of Cumulus Linux to provide better integration between physical and virtual networks, Conde said.
"Cumulus runs directly on the switch hardware and gives insight into the physical network," Conde said.
"If you're running an overlay virtual network, it is abstracted away from the physical underlay network. If you are having performance problems and need to troubleshoot, you are one step removed. That is a problem for people in production networks. But if you have software that runs closer to the switch, you have a better capability for troubleshooting and doing other stuff like traffic engineering, QoS [quality of service] and providing the right kind of visibility into the network for both owners of the network and, in theory, cloud tenants running on the infrastructure."